Question about Evohome Install

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  • nickb23
    Automated Home Lurker
    • Nov 2013
    • 9

    Question about Evohome Install

    Hi Guys,
    I am finally getting my Evohome installed tomorrow as I was waiting to have a new hot water tank installed. I have a vented system, and I will be running 10 HR92 valves. I also bought the base kit and the hot water kit. The hot water tank is now under the boiler, so my question is do I need to install separate wireless relay boxes (bdr91) for the boiler and hot water tank, even if they are going to be next to each other?? Is this also quite straight forward for a plumber to install? I am fine with the setup, its just the connection to the boiler and tank I am not too sure about..

    Also with the hr92's installed, i have had them setup for a while running with the normal programmer as a test, and I have noticed that they need to be calibrated for each room - the temp seems to be a bit off. Is this usual to have to do this??

    Thanks guys. Nick
  • HenGus
    Automated Home Legend
    • May 2014
    • 1001

    #2
    Signing up to this site will provide you with most of the information that you need:



    I have an unvented tank with two motorised valves. Both valves are controlled (CH and HW) and both have their own BDR91 - separated by the required distance.

    Temperature Compensation. I assume that this is what you are talking about:

    Parameter 8 – Temperature offset
    Since the radiator controller measures the room temperature in the area of the radiator, it is possible that this temperature deviates from the temperature measured at a different point in the room.
    If, for example, 20 °C is measured in the room and 21.0 °C at the radiator, this effect can be compensated by an offset of –1.0 °C. NB: the factory offset setting is 0 but it can be adjusted in the range +3 to -3C.

    Rather than fiddle with the HR92, I tend to make the adjustment on the target temp on the controller.

    Comment

    • Rameses
      Industry Expert
      • Nov 2014
      • 446

      #3
      Nick - The BDR91 is a wireless relay. The above configuration you descibe depends on how your heating is setup. For instance I have a 'Y' plan and therefore have a BDR for each setting on the valve (one for HW and other for CH) - with a BDR on the boiler to control the firing. The training mentioned will help. But there are many installers out there who can help also. Even if its just to wiring it in.

      Temp calibration - this is a big topic which comes up ALL the time. We have calls from people who are measuring the temp by holding thermometer next to the device and expecting a correlation (not realising their hand is providing added heat etc), and others that have many sensors in the room and see hot and cold spots even within their space. The HR92 measures the upwards draught temp. The air rising from the floor. (sensors are behind the LCD). Due to the way thermo dynamics of the room this is the best gauge of the 'last' tempertature of the room. (imagine the air circulating, rising flowing across the room, cooling, falling down and then coming back to the raditator) The fuzzy logic computer then uses this data to constantly measure the room's behaviour. The evohome system attempts to keep the room at a regulated temperature. Some days it will over shoot, to allow for the gradual fall (giving the longest average). It takes 7-10 days for the evohome system to fully learn the signature of the room. Once done it is constantly learning after that.

      My advice - go on what you feel and adjust accordingly. There are deeper settings within the HR92 to allow for adjustments, but we have found in most cases the HR92 is correct in judging the rooms ambient temp.
      getconnected.honeywell.com | I work for Honeywell. Any posts I make are purely to help if I can. Any personal views expressed are my own

      Comment

      • HenGus
        Automated Home Legend
        • May 2014
        • 1001

        #4
        Rameses - I am following this thread and your detailed explanation above is most helpful. Now that Winter seems to have arrived, my CH is on and I have noticed that the TRVs in some rooms overshoot - but we are early in the 10 day period. A follow on question if I may? In some rooms, the HR92s are more active than in others (depending on how the room is used). Is battery life really 2 years as stated by Honeywell? What quality of batteries are people tending to use? The ones supplied look to be pretty standard. Any thoughts on re-chargeable battery use? I am assuming that knowing when the batteries need replacing is just a case of keeping an eye on each and every TRV. I have 21!

        Comment

        • Rameses
          Industry Expert
          • Nov 2014
          • 446

          #5
          Batteries - I am 9 months in on my install, (so had the tail end of Spring) and I am on 2 out of 3 bars. Honeywell does state 2 years as a guide under normal use. It should do 2 heating seasons which in theory is , 3 years (if you get my math). Obviously this depends on the battery. Market stall cheap ones will perform exactly as they do on Christmas day - dissapointingly. The ones supplied by Honeywell are above standard grade. (you can tell by the weight). Honeywell would advocate use common sense. Many long life batteries found in supermarkets or branded products are more than enough. You could do rechargeables, but - the 'lossy' nature of rechargeables is more significant than standard batteries (ie if left alone a rehcargeable battery discharges on its own accord, where as static batteries have a longer shelf life) - and considering we are talking 'years' and not months. I think rechargable batteries would need to be 'revisited' a lot more.

          Overshoot - Honeywell is creating a whitepaper on this to help people understand why the controls do what they do. It also depends on what you measure as an over shoot. Getting like for like temperature readings is hard. (eg we have people hold thermometers next to the HR92, expecting to see the same temp. But our HR92 also takes into account radiator distance / radiation.)
          Within 10 days you can expect your HR92's to be very very very active. Especially right now. And even occupancy has an impact (100-150w per person) This is becuase they are desperatly learning the cause and effect of what they do to your room. When Honeywell deliver this 'whitepaper' you will see just how much work they do with PWM (pulse width modulation) and how a boiler really should work (effectively)

          I hope this helps a little - I will post the whitepaper link as soon as its done. In the meantime try to leave it alone :-)

          PS Dont worry about keeping an eye on them - the unit will tell you centrally on the controller when the batteries need replacing (and in which room)
          Last edited by Rameses; 26 November 2014, 11:09 AM.
          getconnected.honeywell.com | I work for Honeywell. Any posts I make are purely to help if I can. Any personal views expressed are my own

          Comment

          • SensibleHeatUK
            Moderator
            • Feb 2009
            • 228

            #6
            Two years from the reasonable quality AA batteries is not an over-statement, I'd recently changed the batteries in my HR80s fitted to towel rails in my house (room heating is via wet underfloor) as I'd just started to get the low battery warning. On opening up the battery compartment I realised they were still using the original batteries from 2007! I also went round and changed the batteries in my HCF82s as these were also the original batteries for the same period! So depending on how much the motors move then the batteries should easily last 2 years.

            Rechargeable batteries are not recommended as their voltage drops dramatically as they discharge which will give you battery warnings very soon after fitting.
            Sensible Heat
            SensibleHeat.co.uk

            Comment

            • HenGus
              Automated Home Legend
              • May 2014
              • 1001

              #7
              Thanks both: your knowledge and time is appreciated. There are clearly significant gaps in my knowledge about this system. I was not aware, for instance, that I would get battery warnings on the controller. Having had the system in operation for the past few days, even my slightly sceptical wife is starting to see the advantages of zoning.

              Comment

              • nickb23
                Automated Home Lurker
                • Nov 2013
                • 9

                #8
                Just want to say thanks for all your input. We have had a few delays and the plumber came around today. Unfortunately he had some difficulty setting up the new system. I did give him the number for evohome store post sales support but they were busy with an installation. He is coming back on Saturday to finish up but I want to get as much info for him as possible. I have seen the different wiring plans but not too.sure what one I have. If I describe what I have hopefully you guys can point me in the right direction.

                We have an open vented system. We have had a new cold tank and new hot tank installed. Pretty much the only thing being kept is the boiler (glow worm) and rads. We have 2 controls. One is a programmable control for the central heating and hot water. And the other one is a dial thermostat. We have also had new pumps installed and a 3 port something. It is really just trying to get the the 2 transmitters attached to the boiler and hot water tank. After that I can do the rest. Again any help would be greatly appreciated. Thanks. Nick

                Comment

                • Rameses
                  Industry Expert
                  • Nov 2014
                  • 446

                  #9
                  1) Get your plumber to ring the the installer line - the getconnected/evohome line is for consumer pre-sales - Installers can ring the professional number here http://www.honeywelluk.com/contact/ (08457 678999 is available from: Monday -Thursday 09:00 - 17:00 Friday 09:00 - 16:00)

                  2) He should have taken the training - if not then quickly do (or you do) http://youlearn.honeywelluk.com/ - anyone can take this - and after the small session - I reckon this will answer most if not all of your questions.

                  3) If you really get stuck (which you shouldnt do as what you have is a normal instal - DM me your installers details and we will contact him

                  What you decribe is a simple install - more wiring than plumbing. (assuming valves on radiators are ready) - and I appreciate this could be confusing. But you describe a Y plan system which is well within scope of many installers. We know many installers find it a little daunting - which is why we are trying to encourage as many as possible to not just open up the manual.
                  getconnected.honeywell.com | I work for Honeywell. Any posts I make are purely to help if I can. Any personal views expressed are my own

                  Comment

                  • nickb23
                    Automated Home Lurker
                    • Nov 2013
                    • 9

                    #10
                    Thanks Rameses
                    My Plumber and I had a good punt at getting it all wired. At the moment we have working rads and hot water, which is excellent. I do have a couple of questions regarding the system. Some of these might seem very basic, but I have ever only had Combi Boilers, so stored hot water is new to me :-)

                    1. We have wired it as a Yplan. The 2 BDr91's have been binded, and is working. My question is to do with the DHW one. It the wiring Diagram, it has the grey cable from the 3 port valve going to 7. There is another wire coming from 7 and going into the DHW BDR91. It does not say where it should go in the reciever. Where do I wire it in?? It is Figure 10 in the installation guide.

                    2. What is the best way to set the hot water for use in the morning and evening? How good are new hot water tanks at retaining heat??

                    3. This question is just one to work out how the system works and what it does to actually put the heat on. If it is 11 at night (heat schedule is off for the whole house) and I turn the living room heating on via the controller. This then sends the signal to the TRV to change the temp. Is there then a seperate signal to the boiler to turn on the boiler?

                    4. If I turn on the heating or hot water using one of the quick commands, should the boiler come on instantly, or like with the TRV's it might take up to 4 minutes?

                    5. On the 2 BDR91's does the green light mean that it is on, or can they be on without the green light on?

                    6. This one is for all the users who have had it for a while. Are there any suggestions or tips on different settings on the trv's and controller??

                    7. From my boiler, there seems to be 2 wires coming out. Both have the same L,N,E. We have wired them up the same... Is this correct??

                    8. Not so much to do with the Evohome, but we have also had a new Honeywell 3 port valve installed. It is set to Auto, but now and then it ticks. Anything I need to worry about??

                    Thanks, and sorry for all the questions..


                    Nick

                    Comment

                    • HenGus
                      Automated Home Legend
                      • May 2014
                      • 1001

                      #11
                      Nick,

                      A few points based on trial and error and 6 months with the Evohome system. I have 21 TRVs in 12 zones in a 5 bed house (built 2000)

                      1. Educate the family to close room doors if you want the maximum zoning benefit.

                      2. Set target temps and times for the zones that you use frequently - put the rest on frost protection. I use 8C. You do not need to anticipate the time when you want the set temp as the TRVs/controller will do the thinking for you based on various factors including OAT (if you have the gateway). If the target temp is too low then you can adjust the valve parameters or, alternatively, just tweak up the target temp. 20C in a sunny room feels different from 20C at the back.

                      3. In multi-TRV zones think carefully about which TRV provides the temp link to the controller. My installer didn't really give this one much thought; e.g., we have a bedroom with an en-suite. Logic would suggest that the lead TRV should be in the bedroom but not if it is behind long curtains or boxed in by furniture.

                      4. The TRVs have to learn so initially there is a considerable amount of valve whirring. It does reduce but the valves are very active.

                      5. Yes, the green BDR lights are on when there is heat demand for the CH and HW.

                      6. Modern - well insulated - HW cylinders lose very little heat. I have my temp set in the range 60 to 55C as we have thermostatic valve showers that require a minimum input temp. HW heating demand is set for 7 to 10am and 5 to 8pm. We have all the HW that we need but there are only two of us. If my wife has a bath before bed, then the HW is back at 60C before I have my shower at 7.30am.

                      7. When CH is ON it is ON (depending on the zone target temps for each of the zones). Evohome is not like the old thermostat and time switch arrangement. If you set the zones a target temp of 8C (at least in our house) there is only the occasional demand for heating overnight. We had a cold night a week ago and the pump came on at about 4.30am for 30 minutes. My guess is that it was topping up the temp in a bedroom that we have over a garage.

                      So how are we using the system? With only 1 bedroom in use for most of the time, the other 4 are on frost protection until required for use. Our bedroom has a target temp of 18C at 7.30 as does our kitchen/family room, hall and landing and study. The target temps in these rooms are reduced to 15C for the rest of the day (from 10am onwards) with the exception of our kitchen/family room which is set at 18C. In the evening, we heat the living room to 20C and set a target temp of 15C for our bedroom from 9pm through to 1030pm. Heating has yet to come on as our bedroom is above our living room.

                      Finally, is it saving us lots of money? My guess is that we are saving money but even my sceptical wife admits that the rooms that we use are more comfortable. A quick check of my gas consumption shows that over the past month our gas consumption has risen by £1.20 a day to cover the CH (about £2 a day including HW and standing charge). I cannot comment on the technical side of things other than to say that we have an unvented HW system and system boiler. Evohome controls the two motorised valves which, in turn, control the boiler. Put simply, Evohome has replaced the old links from the wall thermostat and the timer/tank sensor. Enjoy.

                      Comment

                      • SensibleHeatUK
                        Moderator
                        • Feb 2009
                        • 228

                        #12
                        Regarding the Y-Plan wiring, you must ensure that the grey wire is energised when you do not want hot water so that the valve responds correctly. The diagram in the Honeywell guide shows the grey wire going to the correct BDR, however it does not show that it connects to the "C" terminal, which is the Normally Closed side of the internal relay.
                        Sensible Heat
                        SensibleHeat.co.uk

                        Comment

                        • nickb23
                          Automated Home Lurker
                          • Nov 2013
                          • 9

                          #13
                          Thanks guys.

                          SensibleHeat. So I wasn't being dumb then, was I?? When I get home I will put a link from the grey cable to the c terminal on the DHW BDR91. Thanks. Nick

                          Comment

                          • nickb23
                            Automated Home Lurker
                            • Nov 2013
                            • 9

                            #14
                            Ok, so I have come home and "temporarily" wired the C terminal form the DHW BDR91 to the grey cable from the 3 port valve. So far so good. I still have heating and hot water.. I have taken pictures of my 2 BDR91's to make sure that I have done them right. The one with an H is the Heating, and the other is DHWIMG_20141215_185824[1].jpg IMG_20141215_190016[1].jpg

                            I have also attached a photo of the wiring box underneath the boiler. As I said previously the boiler had 2 cables coming from it. Cable 1 had the standard Brown, Blue and Yellow Green, and was labelled as Pump Live, Pump Neutreal and Earth. Cable 2 had 4 cables. Brown (Mains Live), Grey (Switch Live)Blue (Frost Stat) and Earth. There was also a link cable between the Pump Live on Cable 1 and Mains Live on Cable 2.


                            IMG_20141215_205433[1].jpg.

                            Where do these fit in with the wiring diagram???


                            Thanks guys.

                            Nick

                            Comment

                            • The EVOHOME Shop
                              Site Sponsor
                              • Dec 2014
                              • 483

                              #15
                              Hi Nick,

                              Why are there two wires sharing the BRD91's terminal A (link wire from 2nd L and a second grey wire)?

                              The 'pump wire' from the boiler is to allow the boiler to control the pump for 'pump overrun' (cooling of the boiler heat exchanger). I am not sure why someone has linked out the pump live wire - maybe the pump overrun function on the PCB failed at some point and the installer was lazy? In this case what turns the pump off if it has a permanent live feed? The 'pump' wire has no function with the evohome wiring diagram and the only thing coming back from 'evohome' should be power on the switched live when the motorised valve actuates.

                              If you look at page 47 of the evohome installation manual (in your individual case if the system is wired correctly) terminal 8 should be connected to the 'switched live' wire of your boiler and nothing else.

                              Hope that helps.

                              Richard

                              Comment

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