Electronic TRV's 2012

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  • chris_gla
    Automated Home Jr Member
    • Jan 2009
    • 13

    Electronic TRV's 2012

    I still have a bimetal roomstat in hall with wax Danfoss TRV's on 13 of the 14 radiators in house (hall currently has lockshield).

    Was considering getting a wireless roomstat to improve temperature stability in lounge but noticed the price of electronic TRV's has come down a lot.

    Has anyone tried any of the budget Conrad options (or other suggestions)?:-

    The EQ3 at £15.99


    The Eurotronic Sparmatic Comet at £15.97


    The HSA9001A at £19.99 (reduced from £49.99... too good a bargain for a Scotsman! )


    Or, for around £26 a room an RF option:-



    The Pegler iTemp also looks like a good option at £23 and has USB programmer, window sensor and remote programmer options for around (plus most importantly UK manuals and support).
    This would cost aorund £370 for including 14 valve thermostats, a remote, one sensor for patio doors and a USB programmer but the UK support, etc seem to make this quite a good option....


    Think my current TRV's are Danfoss RA.

    I looked at Honeywell/ Conrad HS20 "full" systems but for 14 radiators cost is a lot higher (circa £1000) and I'm not sure I need the features of the "integrated" systems.

    The main advantage of "integrated" wireless TRV systems seems to be a pump control relay- but reading other forums it seems that I'd be better replacing my "fixed speed" Grundfos pump with a Grundfos Alpha 2- less power and dynamic "load sense" means I don't need any radiators left with lockshield and no TRV, or a roomstat. (Note I on't have a combi boiler- system is boiler + boilermate 2000 heat store)

    Anyone tried any of these budget options- 14 zone system for circa £250 plus £120 for a new high efficiency pump seems pretty good and may actually payback in 2 - 4 years...(unusual for my HA "investments")
    Last edited by chris_gla; 1 May 2012, 02:23 AM.

  • #2
    I haven't used any of these models, but in my experience you always get what you pay for so it may be worth splashing out! Don't forget to check the warranty lengths for each product and read as many reviews as you can. Hope this helps!

    Comment

    • CHRISMU
      Automated Home Lurker
      • Jun 2012
      • 9

      #3
      Radiator without trv is not to allow flow if trv`s have closed

      Originally posted by chris_gla View Post
      I still have a bimetal roomstat in hall with wax Danfoss TRV's on 13 of the 14 radiators in house (hall currently has lockshield).

      Was considering getting a wireless roomstat to improve temperature stability in lounge but noticed the price of electronic TRV's has come down a lot.

      Has anyone tried any of the budget Conrad options (or other suggestions)?:-

      The EQ3 at £15.99


      The Eurotronic Sparmatic Comet at £15.97


      The HSA9001A at £19.99 (reduced from £49.99... too good a bargain for a Scotsman! )


      Or, for around £26 a room an RF option:-



      The Pegler iTemp also looks like a good option at £23 and has USB programmer, window sensor and remote programmer options for around (plus most importantly UK manuals and support).
      This would cost aorund £370 for including 14 valve thermostats, a remote, one sensor for patio doors and a USB programmer but the UK support, etc seem to make this quite a good option....


      Think my current TRV's are Danfoss RA.

      I looked at Honeywell/ Conrad HS20 "full" systems but for 14 radiators cost is a lot higher (circa £1000) and I'm not sure I need the features of the "integrated" systems.

      The main advantage of "integrated" wireless TRV systems seems to be a pump control relay- but reading other forums it seems that I'd be better replacing my "fixed speed" Grundfos pump with a Grundfos Alpha 2- less power and dynamic "load sense" means I don't need any radiators left with lockshield and no TRV, or a roomstat. (Note I on't have a combi boiler- system is boiler + boilermate 2000 heat store)

      Anyone tried any of these budget options- 14 zone system for circa £250 plus £120 for a new high efficiency pump seems pretty good and may actually payback in 2 - 4 years...(unusual for my HA "investments")

      Hello Chris,


      I am a Heating Engineer - although I cannot advise You regarding the Controls that You mentioned I wanted to alert You to something that You MAY have the wrong impression about regarding NOT needing a Room Thermostat and the Radiator that does NOT have a TRV:


      Without a Room Thermostat the Boiler will keep `Cycling` - Firing Up in order to Satisfy the setting on the Boiler Thermostat - You MUST have a Room Thermostat - ideally a Programmable Room Thermostat which can be Set for different Temperatures at different periods of the Day & Night.

      Thermostatic control is actually a requirement of the Building Regulations - `Part L` - the Energy Efficiency details within these Regulations applies to ALL Heating System Installations - and significant Upgrades / alterations - NOT just to New Build Homes / New Heating System Installations.

      The Room Thermostat forms part of what is called `Boiler Interlock` - regarding the Heating System Controls.

      Apart from the Regulations aspect You would be `Throwing Money Away` to run a Heating System that does NOT have a Room Thermostat.

      This Thermostat is usually fitted in the Hallway - enough distance away from the Radiator to make sure that it is NOT Turning Off the Boiler prematurely - before the rest of the Home / System - this of course is VERY dependent on the Hallway being of a reasonable size and the Radiator being of the correct size to correctly heat that space.

      The Radiator in the area where the Room Thermostat is located MUST NOT have a TRV - because the Heat Up of the Hallway - or other Room Thermostat location - is `controlling` the Boiler Firing process and therefore when the Heat is circulating around the rest of the Heating System pipework.

      This Radiator should NEVER be turned Off when the Heating is operating - although Homes that have a very small Hallway [and Room Stat in Hallway] sometimes do have the Hall Radiator turned Off so that the Room Thermostat is operated from Heat coming out of the Rooms that connect with the [Small] Hallway - in these circumstances the Room Thermostat may be better located elsewhere - depending on the property layout.

      The lack of a TRV on a Radiator that is in the location where the Room Thermostat is fitted is NOT to enable the Heating Flow and Return to be able to Circulate IF all the TRV`s were ever to Turn Off at the same time - which is very unlikely unless others were Manually turned Off and then the others closed down on the Temperature Setting.

      The correct procedure for a Hall Radiator in a average sized Hallway where a Room Thermostat is fitted in the Hallway is to fit 2 Lockshield Radiator Valves - so that the Radiator cannot be turned Off - again the Radiator must be the correct size to correctly heat the Hallway / Room Thermostat location - Or the Boiler would NOT be firing for the correct periods of time to Heat the Home correctly.


      The Grundfos Alpha 2 is definitely the Pump that I would Install [if replacing a Grundfos 15/50 or 15/60] and I have replaced the Grundfos 15/60 in My own Home with one of these - the Pump modulates when it `senses` a change in Flow from for example TRV`s closing - so the Power usage is not at maximum all the time that the Pump is running - a small saving in electricity.

      As with any Heating System there MUST be provision for circulation of the water - most modern Boilers require that a Bypass is installed reasonably close to the Boiler - Regulations now specify that an Automatic Bypass Valve is installed [Again `Part L`] - this is to prevent circulating the Heating Flow & Return around the Bypass when unnecessary - i.e. when the System is operating to circulate Heat around the Home.

      The Bypass should ONLY operate when the Circulation around the System is NOT required - for example when the Heating / Hot Water Zone Valves [Motorised Valves] are Closed - in order to Dissipate Heat from the Boiler.

      If You don`t already have one - You may want to consider installing an Automatic Bypass Valve when You have the System Drained down to fit the new TRV`s and Pump - the prevention of circulation around an `Always Open` Bypass will improve the System Heat Up time as the Heated Water will be circulating around the Flow and Return only - NOT through an Open Bypass.



      Whatever Radiator Controls that You select these Important Points MUST be observed or You will be spending quite a lot of Money and NOT Controlling the Heating System correctly.


      I hope that this is helpful - Sorry if this is `Too Late` - I have only just become a Forum Member.


      Regards,


      Chris - Heating Engineer - Heating, Plumbing & Gas Contractor.
      Last edited by CHRISMU; 30 June 2012, 10:15 PM.

      Comment

      • CHRISMU
        Automated Home Lurker
        • Jun 2012
        • 9

        #4
        "Hello All",

        I noticed when I submitted the previous Post that several words had become disrupted - I had to Edit the post a few times to rectify this.

        I apologise to any Members who read the Post before I noticed this - some of the Words had become very strange !

        I have seen this before on other Forums - usually If the Spell Checker has been used - I don`t think that this is the case on here - nor do I think that this is anything to do with My Browser [?] or Windows 7 [?].

        Chris

        Comment

        • neilhooper
          Automated Home Guru
          • Oct 2008
          • 124

          #5
          Originally posted by CHRISMU View Post
          Hello Chris,


          I am a Heating Engineer - although I cannot advise You regarding the Controls that You mentioned I wanted to alert You to something that You MAY have the wrong impression about regarding NOT needing a Room Thermostat and the Radiator that does NOT have a TRV:


          Without a Room Thermostat the Boiler will keep `Cycling` - Firing Up in order to Satisfy the setting on the Boiler Thermostat - You MUST have a Room Thermostat - ideally a Programmable Room Thermostat which can be Set for different Temperatures at different periods of the Day & Night.

          Thermostatic control is actually a requirement of the Building Regulations - `Part L` - the Energy Efficiency details within these Regulations applies to ALL Heating System Installations - and significant Upgrades / alterations - NOT just to New Build Homes / New Heating System Installations.

          The Room Thermostat forms part of what is called `Boiler Interlock` - regarding the Heating System Controls.

          Apart from the Regulations aspect You would be `Throwing Money Away` to run a Heating System that does NOT have a Room Thermostat.

          This Thermostat is usually fitted in the Hallway - enough distance away from the Radiator to make sure that it is NOT Turning Off the Boiler prematurely - before the rest of the Home / System - this of course is VERY dependent on the Hallway being of a reasonable size and the Radiator being of the correct size to correctly heat that space.

          The Radiator in the area where the Room Thermostat is located MUST NOT have a TRV - because the Heat Up of the Hallway - or other Room Thermostat location - is `controlling` the Boiler Firing process and therefore when the Heat is circulating around the rest of the Heating System pipework.

          This Radiator should NEVER be turned Off when the Heating is operating - although Homes that have a very small Hallway [and Room Stat in Hallway] sometimes do have the Hall Radiator turned Off so that the Room Thermostat is operated from Heat coming out of the Rooms that connect with the [Small] Hallway - in these circumstances the Room Thermostat may be better located elsewhere - depending on the property layout.

          The lack of a TRV on a Radiator that is in the location where the Room Thermostat is fitted is NOT to enable the Heating Flow and Return to be able to Circulate IF all the TRV`s were ever to Turn Off at the same time - which is very unlikely unless others were Manually turned Off and then the others closed down on the Temperature Setting.

          The correct procedure for a Hall Radiator in a average sized Hallway where a Room Thermostat is fitted in the Hallway is to fit 2 Lockshield Radiator Valves - so that the Radiator cannot be turned Off - again the Radiator must be the correct size to correctly heat the Hallway / Room Thermostat location - Or the Boiler would NOT be firing for the correct periods of time to Heat the Home correctly.


          The Grundfos Alpha 2 is definitely the Pump that I would Install [if replacing a Grundfos 15/50 or 15/60] and I have replaced the Grundfos 15/60 in My own Home with one of these - the Pump modulates when it `senses` a change in Flow from for example TRV`s closing - so the Power usage is not at maximum all the time that the Pump is running - a small saving in electricity.

          As with any Heating System there MUST be provision for circulation of the water - most modern Boilers require that a Bypass is installed reasonably close to the Boiler - Regulations now specify that an Automatic Bypass Valve is installed [Again `Part L`] - this is to prevent circulating the Heating Flow & Return around the Bypass when unnecessary - i.e. when the System is operating to circulate Heat around the Home.

          The Bypass should ONLY operate when the Circulation around the System is NOT required - for example when the Heating / Hot Water Zone Valves [Motorised Valves] are Closed - in order to Dissipate Heat from the Boiler.

          If You don`t already have one - You may want to consider installing an Automatic Bypass Valve when You have the System Drained down to fit the new TRV`s and Pump - the prevention of circulation around an `Always Open` Bypass will improve the System Heat Up time as the Heated Water will be circulating around the Flow and Return only - NOT through an Open Bypass.



          Whatever Radiator Controls that You select these Important Points MUST be observed or You will be spending quite a lot of Money and NOT Controlling the Heating System correctly.

          I'm a Heating Engineer also and I couldn't have put it any better myself. The only thing that I would add is that if it is feasible and if your are going to use a wireless thermostat you could consider putting it in the coldest ground floor room in the house. You'll know which one this is. The theory being that if you warm the coldest room up you can always control the heat downwards using your TRV's in the other rooms. One thing that Chris hasn't mentioned, never put a thermostat in a room where there is another uncontrolled heat source, i.e. Open fire, Wood burner etc. If the alternative heat source is on, the room warms up and the boiler turns off = rest of the house cold. You would be surprised how many of these we come across !!!

          - Neil

          Comment

          • CHRISMU
            Automated Home Lurker
            • Jun 2012
            • 9

            #6
            Originally posted by neilhooper View Post
            I'm a Heating Engineer also and I couldn't have put it any better myself. The only thing that I would add is that if it is feasible and if your are going to use a wireless thermostat you could consider putting it in the coldest ground floor room in the house. You'll know which one this is. The theory being that if you warm the coldest room up you can always control the heat downwards using your TRV's in the other rooms. One thing that Chris hasn't mentioned, never put a thermostat in a room where there is another uncontrolled heat source, i.e. Open fire, Wood burner etc. If the alternative heat source is on, the room warms up and the boiler turns off = rest of the house cold. You would be surprised how many of these we come across !!!

            - Neil

            ""Hello Neil",

            Thanks for your compliment - always good to read an `endorsement` from a fellow Professional.

            I agree with your VERY Important points regarding the Room Thermostat location - especially in regard to particularly Cold room / area and the information about the Additional Heat Source.


            I did not try to cover all points that should be considered about upgrading the Controls etc. on a Heating System - I wanted mainly to explain about why Chris should NOT dispense with a Room Thermostat and why a Radiator in the area where the Room Thermostat is located should NOT have a TRV or Wheel Head Radiator Valve - and that this is NOT because of allowing one Radiator to be `Open` to circulate water.

            That led Me to explain about the Automatic Bypass.


            As You know We could fill Pages and Pages IF trying to explain everything about Upgrading a Heating System Controls - I thought that I had written `Well Enough` in My long Post [for fear of putting other Members off reading it] - and it MAY never even be read by Chris ? - His Post was 2 Months ago.

            I did not receive any `Notification` Email from the Forum after You Posted your message - so He may not ever see these Posts [?].

            I hope that He does or He will have some VERY Expensive Gas Bills if running a Heating System without a Room Thermostat !


            Thanks again Neil - good to read your valuable advice to Chris and other Members.


            Chris


            EDIT: I did receive a notification Email about your Post - at approx. 00:20 Hrs [Sunday] - after I had wriiten and Posted this Message.
            Last edited by CHRISMU; 1 July 2012, 12:23 AM.

            Comment

            • CHRISMU
              Automated Home Lurker
              • Jun 2012
              • 9

              #7
              Lost words from previous post`s paragraph

              Originally posted by CHRISMU View Post
              "Hello All",

              I noticed when I submitted the previous Post that several words had become disrupted - I had to Edit the post a few times to rectify this.

              I apologise to any Members who read the Post before I noticed this - some of the Words had become very strange !

              I have seen this before on other Forums - usually If the Spell Checker has been used - I don`t think that this is the case on here - nor do I think that this is anything to do with My Browser [?] or Windows 7 [?].

              Chris


              When I carried out the Edits that I mentioned above - somehow due to the Words disruption / merging and Me having to delete merged words some words were `lost` from the paragraph below - this is how it should have read:


              This Thermostat is usually fitted in the Hallway - enough distance away from the Radiator to make sure that it is NOT Turning Off the Boiler prematurely - before the rest of the Home / System has Heated Up - this of course is VERY dependent on the Hallway being of a reasonable size and the Radiator being of the correct size to correctly heat that space.


              The missing words were `has Heated Up` - quite important to make sense of what I wrote - I had not previously noticed this.


              Chris

              Comment

              • neilhooper
                Automated Home Guru
                • Oct 2008
                • 124

                #8
                Chris,

                I wouldn't worry whether Chris gets to read your reply, my reply or any other reply. The main thing is that a lot of people who are just browsing the forums or who are searching for particular items will read it. If someone reads it and they 'do it properly' as a result then our job is done.

                - Neil

                Comment

                • CHRISMU
                  Automated Home Lurker
                  • Jun 2012
                  • 9

                  #9
                  Originally posted by neilhooper View Post
                  Chris,

                  I wouldn't worry whether Chris gets to read your reply, my reply or any other reply. The main thing is that a lot of people who are just browsing the forums or who are searching for particular items will read it. If someone reads it and they 'do it properly' as a result then our job is done.

                  - Neil

                  Hello Neil,

                  My only reason for writing My message to Chris was to try and help Him and prevent Him spending quite a lot of money on Digital TRV`s and dispense with a Room Thermostat only to have put Himself into a far worse position regarding `Energy Efficiency` and also costing Him a lot more money on His Gas Bills.

                  Although I saw that His Post was from May 1st - because I thought that these `Upgrades` would perhaps be carried out in the Summer Months - I thought that My message might have been read before the Works were carried out.

                  Obviously I do hope that what I wrote will benefit other Members / readers on the Forum.

                  The reasons for My comment about Chris reading what I wrote are - firstly I was letting You know why I wrote about ONLY the points that He seemed to be under the wrong impression about - and secondly My was statement that I had not received a notification Email from the Forum - which was the case when I was writing My message - meant that I wondered whether He would ever be notified about My message.

                  The notification Email was delivered afterwards this was probably just the result of a delay in the Email system.


                  Your very important points were well made and definitely added to what I wrote and would benefit Chris and other readers.


                  But it was never My intention that My message should contain any more than information about the points that I perceived Chris might not have the correct information about.


                  I know that both You and I could write very extensively about Upgrading Heating Systems or Upgrading Heating System Controls.

                  But if it seemed necessary to Us to help a Member with ALL the information required We would probably refer them to `Part L` and perhaps give Links to the relevant sections - then adding Our own advice [such as You Posted here] and answering questions that would almost invariably result from their interpretations of what they read in `Part L`.


                  Thanks again Neil for your messages - I look forward to reading Your advice to other Members in the future.


                  Chris
                  Last edited by CHRISMU; 2 July 2012, 09:09 PM.

                  Comment

                  • chris_gla
                    Automated Home Jr Member
                    • Jan 2009
                    • 13

                    #10
                    thanks for the info Chris... the idea for having all TRV with no room stat or bypass with a Grundfos Alpha came from another forum...

                    I think the view was right to a degree as on the system I have the room stat doesn't control the boiler directly, but does via a Boilermate thermal store. This may stop the cycling to a degree, that said it doesn't get away from the part L need for boiler interlock and that although the Alpha will modulate it's just not a good idea running it into a "closed circuit"!

                    I think I've came down to one of three systems- none have a "room stat" but all have a boiler interlock which any of the digital wireless TRV's can control:-
                    1) Honeywell Evo, CM zone or similar using HR80 wireless TRV's. Very good, circa £50 per room but web control seems expensive
                    2) Lightwave RF. Similar to the Honeywell system but a bit more open standards due to other Lughtwave RF kit/ controllers being available.
                    3) Danfoss Living Connect. Contacted Danfoss about this as a few places have them but they aren't officially released in the UK until later in 2012. Again, wireless TRV's but this time they use Zwave meaning you could use a Zwave PIR for instance to detect a room being occupied and switching on/ increasing temp in any room.

                    All three have boiler interlock which replaces room stat to turn any traditional TRV system into multizone only by changing the TRV head- not the complete valve. They all have some degree of fuzzy logic to reduce cycling, exercise closed valves weekly, etc.

                    Pegler have quite a few references on their site which show potential savings and I can see how these would work for my lifestyle (close bed TRV's most of the day, only open office TRV when I'm actually in the house and it's a work day, allow remote control of other TRV's for when I know there is no one at home). Pegler are cheaper but are just TRV heads with no interlock/ remote option so not so good for my use.

                    As it stands I'll probably wait until the Danfoss Living Connect become available and then buy a few of them plus either a Danfoss or Horstmann Zwave boiler interlock to get started and as a "basic" reliable system, then add a Vera controller for remote options and more clever stuff over the top.

                    All in it looks like around £1500 for everything but it isn't unreleastic to think that I could save £200 - £300 a year (15 - 25%) by automating some tasks.

                    The new pump and hall TRV's are the only bits I'd need to drain system down for- I'm likely to get a heating engineer for this to desludge, etc as the system is now 10 years old.

                    Comment

                    • CHRISMU
                      Automated Home Lurker
                      • Jun 2012
                      • 9

                      #11
                      Originally posted by chris_gla View Post
                      thanks for the info Chris... the idea for having all TRV with no room stat or bypass with a Grundfos Alpha came from another forum...

                      I think the view was right to a degree as on the system I have the room stat doesn't control the boiler directly, but does via a Boilermate thermal store. This may stop the cycling to a degree, that said it doesn't get away from the part L need for boiler interlock and that although the Alpha will modulate it's just not a good idea running it into a "closed circuit"!

                      I think I've came down to one of three systems- none have a "room stat" but all have a boiler interlock which any of the digital wireless TRV's can control:-
                      1) Honeywell Evo, CM zone or similar using HR80 wireless TRV's. Very good, circa £50 per room but web control seems expensive
                      2) Lightwave RF. Similar to the Honeywell system but a bit more open standards due to other Lughtwave RF kit/ controllers being available.
                      3) Danfoss Living Connect. Contacted Danfoss about this as a few places have them but they aren't officially released in the UK until later in 2012. Again, wireless TRV's but this time they use Zwave meaning you could use a Zwave PIR for instance to detect a room being occupied and switching on/ increasing temp in any room.

                      All three have boiler interlock which replaces room stat to turn any traditional TRV system into multizone only by changing the TRV head- not the complete valve. They all have some degree of fuzzy logic to reduce cycling, exercise closed valves weekly, etc.

                      Pegler have quite a few references on their site which show potential savings and I can see how these would work for my lifestyle (close bed TRV's most of the day, only open office TRV when I'm actually in the house and it's a work day, allow remote control of other TRV's for when I know there is no one at home). Pegler are cheaper but are just TRV heads with no interlock/ remote option so not so good for my use.

                      As it stands I'll probably wait until the Danfoss Living Connect become available and then buy a few of them plus either a Danfoss or Horstmann Zwave boiler interlock to get started and as a "basic" reliable system, then add a Vera controller for remote options and more clever stuff over the top.

                      All in it looks like around £1500 for everything but it isn't unreleastic to think that I could save £200 - £300 a year (15 - 25%) by automating some tasks.

                      The new pump and hall TRV's are the only bits I'd need to drain system down for- I'm likely to get a heating engineer for this to desludge, etc as the system is now 10 years old.


                      Hello Chris,

                      Thanks for your reply - You are obviously much more enlightened than I first thought regarding your knowledge of Heating Systems / Your own Heating System - I obviously did not know this when I Posted My message about the Room Thermostat - Automatic Bypass etc.

                      It seems to Me that you have made your well researched selection on which Radiator Digital / RF / TRV`s to use to independantly control the Radiators in your Home - I cannot recommend or otherwise the Danfoss Products that You may have decided on as I have not installed any of them - but Danfoss produce quality products for the Heating Industry and are definitely a well known / well respected / reputable Company.

                      I install mainly Honeywell Heating Controls and I personally feel that they cannot be bettered by any Heating Controls Manufacturer - But You mentioned that The Honeywell Evohome Controls are perhaps offering facilities that you don`t need / want - and at a Cost that can be `beaten` by using the Danfoss System Controls.


                      I hope that You were not offended by what I wrote in My first reply to your Post - I had thought that I was helping a person who did NOT realise the importance of a Room Thermostat / Boiler Interlock and System Bypass etc. - but after receiving your reply I can see that You are NOT a `Novice` in understanding the `Workings` of a Heating System.


                      Good Luck in whatever You finally decide upon - I hope that you configure a Fully Controllable - Energy Efficient Heating System for your Home.


                      Chris
                      Last edited by CHRISMU; 3 July 2012, 12:18 AM.

                      Comment

                      • fredd500
                        Automated Home Jr Member
                        • Jun 2009
                        • 29

                        #12
                        I have installed a number of these: FHT80BTF from Conrad-UK.

                        While they do shut down all the radiators, control of the boiler is achieved through something called an FHT8W boiler interlock. I have installed this in place of my old danfoss 103 timer. When all radiators are closed, the interlock shuts down the boiler. When any one radiator opens more than a set percentage (I have chosed 10%) the interlock comes on and the boiler runs.

                        I do have a bypass radiator - it's in the bathroom but technically I don't believe it is necessary as the boiler pump won't be running unless heat is being demanded elsewhere in the house. Being a towel rad, fitting a TRV to it would be difficult and look odd anyway.

                        My house has never had a room stat anywhere, the conrad system replaced a timer and all TRV'd radiators (no bypass and no interlock). I'm no heating engineer, but it seems to me that having a room stat in the coldest room (usually one you don't actually spend any time in anyway), running the boiler constantly until that room gets warm and artificially throttling back the heat output in other rooms using traditional wax filled TRV's is an approach that is way beyond it's best before life.

                        Just my two penneth worth.
                        Chris

                        Automating my home in a family friendly way - My blog: http://www.cpmills.com/

                        Comment

                        • CHRISMU
                          Automated Home Lurker
                          • Jun 2012
                          • 9

                          #13
                          Originally posted by fredd500 View Post
                          I have installed a number of these: FHT80BTF from Conrad-UK.

                          While they do shut down all the radiators, control of the boiler is achieved through something called an FHT8W boiler interlock. I have installed this in place of my old danfoss 103 timer. When all radiators are closed, the interlock shuts down the boiler. When any one radiator opens more than a set percentage (I have chosed 10%) the interlock comes on and the boiler runs.

                          I do have a bypass radiator - it's in the bathroom but technically I don't believe it is necessary as the boiler pump won't be running unless heat is being demanded elsewhere in the house. Being a towel rad, fitting a TRV to it would be difficult and look odd anyway.

                          My house has never had a room stat anywhere, the conrad system replaced a timer and all TRV'd radiators (no bypass and no interlock). I'm no heating engineer, but it seems to me that having a room stat in the coldest room (usually one you don't actually spend any time in anyway), running the boiler constantly until that room gets warm and artificially throttling back the heat output in other rooms using traditional wax filled TRV's is an approach that is way beyond it's best before life.

                          Just my two penneth worth.

                          "Hello fredd500",

                          I was interested to read that You installed Radiator Valve Controls and a Boiler Interlock Control to your Heating System.


                          Some of my `emphasised` comments are directed at other readers - not You.


                          I agree with most of your comments - But a couple of my comments about a Heating System Controls etc. would be:


                          Having a Boiler Bypass is not only a requirement of Part L of the Building Regulations but most New / High Efficiency Boilers require that Heat is dissipated from the Heat Exchanger when the Thermostatic Control or Time Control shuts off the Boiler during a period when it is `Firing` - in case that the system circulation is stopped at the same time as the Boiler is stopped from Firing.

                          This Bypass should be of a `Minimum Length` - as stipulated by the Boiler Manufacturer But - NOT a very long run of Flow and Return Pipework to for example a `Bypass Radiator` - and must have an `Automatic Bypass Valve` which opens by an increase in pressure IF circulation has been stopped either by Zone Valves closing or all TRV`s being closed / `satisfied` [usually unlikely but not impossible] - NOT a Gate Valve / Lockshield Valve or Radiator Valves.


                          Installing the type of Controls that You have decided upon and installed - WITH the addition of a Boiler Bypass which includes an Automatic Bypass Valve is definitely much better than just ordinary TRV`s and a Room Thermostat - BUT Most people either could not afford these - or would simply not agree to Pay for them if offered as an option for controlling their Heating System - a New System or Existing System `Controls Upgrade`.

                          That is why for Domestic Heating Systems Heating Engineers still recommend / adhere to the `usual method` of satisfying both the Buliding Regulations in `Part L` and installing affordable / easy to use Heating Controls such as Programmers / Timeclocks / Programmable Room Thermostats [and conventional room thermostats] - Radiator TRV`s - Zone Valves and a Boiler Bypass with Automatic Bypass Valve etc.

                          Regarding your comment about having a Room Thermostat in the coldest part of the House and then `artificially throttling back the heat output in other rooms` - this is not really what would be done in practical terms if people find themselves in that position.


                          Although this next comment is NOT at all in adherence with a `Calculated / Technical Approach` it is a practical approach:


                          The occupant of the Home would be advised or find out for themselves that they should Set the Room Thermostat to a lower Temperature than that usually required / imagined - the rest of the Home would still have reached a desireable / comfortable temperature when the Room Thermostat was satisfied - this could easily be determined by trial and error.

                          Although I realise that this is NOT the `Scientific approach` - there are very few Homes where the Room temperatures can be exactly regulated - there will always be some trial and error adjustments regarding temperatures.

                          If the Room Thermostat - which in a `normal domestic heating system` is a requirement of Part L of the Building Regulations is NOT fitted in the `Coldest Area` of the Home then that Room / Area would NOT reach the desired temperature when the Room Thermostat was satisfied - meaning that this Room / Area would possibly remain too `Cool` - depending on whether there was Heat Gain from the surrounding Rooms / Areas.

                          When people have a Heating System that does not have a Room Thermostat or an Efficient form of Boiler Interlock that operates on a Temperature Setting[s] the Boiler will be Firing to satisfy the Boiler Thermostat setting - `Cycling` - this is a VERY serious waste of Gas !

                          If a Heating System is operated in this manner no amount of Radiator TRV`s could make it an `Energy Efficient` / `Cost Effective use of Gas` System.


                          As I mentioned above some of these comments are directed at other readers - especially as You have decided that the previous comments of `Us Heating Engineers` are `Not Up to date` [`an approach that is way beyond it's best before life`].


                          Regards,


                          Chris - Heating Engineer / Contractor and Registered Gas Engineer
                          Last edited by CHRISMU; 5 October 2012, 11:22 PM.

                          Comment

                          • fredd500
                            Automated Home Jr Member
                            • Jun 2009
                            • 29

                            #14
                            Chris

                            Thanks for your reply. This is indeed interesting and although I have to admit that most of it goes over my head, it does make me wonder how poor my installation must be.

                            The background is that I bought a house with an ancient Valliant boiler in it. All rooms had TRVs (and worryingly of about three or four different makes) and a simple Danfoss 103 timer. No central room stat. There was no bypass radiator (later recommended to me by someone else) so the worst case was the timer was on and all rads satisfied so unless there was some sort of internal bypass in the boiler there would have been nowhere for the hot water to go.

                            When that boiler was eventually condemed (by an over zealous BG engineer looking for a quick commission on a new one - don't get me started on that!) I had it replaced with what is possibly turning out to be a bit of a turkey (Baxi 105HE) but it was a straight forward swap out - I don't believe the engineer even power flushed the system. We even left the old 103 timer in place. It was only later that I added a rad in the bathroom and left that open all the time (which reminds me - it was leaking a bit so I closed it - must fix this and re-open tonight!).

                            I do notice that the boiler has some overrun - there is a period of time after the interlock shuts off, that the boiler keeps pumping for before shutting down completely - one assumes this is to remove any residual heat from the heat exchanger? I installed the interlock myself (I think the control system I have goes over the heads of my usual plumbers) and I did this by just working out what the 103 timer was doing (opening/closing a relay in response to the timed programme) and then wiring the interlock in the same manner. It works and has worked for some time. One assumes the relay is simply wired to some internal terminals that would ordinarilly be connected to the thermostat?

                            Chris (fredd500 - way too many Chris' on this post!!!)
                            Chris

                            Automating my home in a family friendly way - My blog: http://www.cpmills.com/

                            Comment

                            • CHRISMU
                              Automated Home Lurker
                              • Jun 2012
                              • 9

                              #15
                              Originally posted by fredd500 View Post
                              Chris

                              Thanks for your reply. This is indeed interesting and although I have to admit that most of it goes over my head, it does make me wonder how poor my installation must be.

                              The background is that I bought a house with an ancient Valliant boiler in it. All rooms had TRVs (and worryingly of about three or four different makes) and a simple Danfoss 103 timer. No central room stat. There was no bypass radiator (later recommended to me by someone else) so the worst case was the timer was on and all rads satisfied so unless there was some sort of internal bypass in the boiler there would have been nowhere for the hot water to go.

                              When that boiler was eventually condemed (by an over zealous BG engineer looking for a quick commission on a new one - don't get me started on that!) I had it replaced with what is possibly turning out to be a bit of a turkey (Baxi 105HE) but it was a straight forward swap out - I don't believe the engineer even power flushed the system. We even left the old 103 timer in place. It was only later that I added a rad in the bathroom and left that open all the time (which reminds me - it was leaking a bit so I closed it - must fix this and re-open tonight!).

                              I do notice that the boiler has some overrun - there is a period of time after the interlock shuts off, that the boiler keeps pumping for before shutting down completely - one assumes this is to remove any residual heat from the heat exchanger? I installed the interlock myself (I think the control system I have goes over the heads of my usual plumbers) and I did this by just working out what the 103 timer was doing (opening/closing a relay in response to the timed programme) and then wiring the interlock in the same manner. It works and has worked for some time. One assumes the relay is simply wired to some internal terminals that would ordinarilly be connected to the thermostat?

                              Chris (fredd500 - way too many Chris' on this post!!!)

                              "Hello again Chris",


                              Thanks for your reply.


                              As You have a Baxi 105 HE Combination Boiler I can give you some `reassurance` regarding a couple of points:


                              This Combi Boiler has an integral `Automatic Bypass` which will allow the Pump Over-run to not be pumping against no circulation in the unlikely event that this were to occur.

                              Depending upon the circumstances regarding the Boiler Interlock this `Built In` Bypass would not really be capable of Heat Dissipation because there is simply not enough pipework to dissipate the Heat - but this should not cause any problems as usually there is always some circulation around the Heating System - unless all the TRV`s were closed at the same time - which could in theory happen.

                              Without checking I think that I remember the Baxi 105 HE has up to a 30 Minute Pump Over-run [?] - an unusually long period of time - and obviously this would mean that the Flow and Returns would have circulation for that period of time.


                              Obviously You already know that there is a Hot Water `Pre Heat` Facility on the Combi which will [if selected] cause the Boiler to Fire Up to Heat the small Hot Water store within the Combi - this would happen frequently - so that will also cause the Pump Over-run to operate frequently although in this case only for approximately 30 Seconds.

                              I assume that You have a Copy of the User and Installation Instructions for the Baxi 105 HE - ? - some of the brief descriptions of operation might be useful to read to see the process / sequence of operation.


                              I cannot comment upon the Wiring for the Boiler Interlock - for two reasons:


                              Without seeing the exact wiring diagrams it would not be possible.

                              And also - since approximately 2005 it has been a requirement under `Part P` of the Building Regulations for Electrical Works to be carried out by a `Competent Person` - this means in law an Electrician who has the necessary Qualifications and is Registered with an Electrical Competent Persons Scheme - for example NICEIC - it would definitely be inappropriate for Me to advise on Electrical Wiring on this Forum or any other.


                              Up to 2005 I had previously been deemed as `Competent` in Essential Electrics and Electrical Installation for Mechanical Services having taken Training and Assessment in those - `ACOPS` - `Approved Code of Practice` Training and Assessment - recognised as `Additional Qualifications` within the Heating and Gas Industries - although hated by Professional Electricians for obvious reasons.

                              I then completed `Training and Assessment` for `Defined Scope` [Heating and Gas Appliances] Part P and I Registered with an Electrical Competent Persons Scheme - this process was `Valid for 5 Years` [Re-register every Year] but as the costs are `prohibitive` for someone who is NOT trading as an Electrician I let this lapse in 2010.

                              These `Defined Scope` Part P Training and Assessment Courses are also hated by most Professional Electricians for the same reason.


                              Because of the Building Regulations in `Part P` and obviously the possible Dangers of carrying out Electrical Works / Testing etc. I feel that I am not able to give any Advice or Information about the Electrical Wiring of Heating Controls etc. on a Forum.

                              My Heating Systems are all wired up by a Fully Qualified and Registered Electrician - any Electrical Faults on New Boilers are obviously covered and dealt with by a Service Engineer from the Boiler Manufacturer under the Warranty - although I would be able to diagnose what component was at fault by various tests.


                              I hope that these comments are of some help Chris.


                              Regards,

                              Chris
                              Last edited by CHRISMU; 5 October 2012, 11:31 PM.

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