Page 2 of 8 FirstFirst 1234567 ... LastLast
Results 11 to 20 of 75

Thread: Question about Evohome Install

  1. #11
    Automated Home Legend
    Join Date
    May 2014
    Posts
    989

    Default

    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.

  2. #12

    Default

    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

  3. #13
    Automated Home Lurker
    Join Date
    Nov 2013
    Posts
    9

    Default

    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

  4. #14
    Automated Home Lurker
    Join Date
    Nov 2013
    Posts
    9

    Default

    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

  5. #15
    Site Sponsor The EVOHOME Shop's Avatar
    Join Date
    Dec 2014
    Location
    Powys, Mid Wales
    Posts
    479

    Default

    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

  6. #16
    Automated Home Lurker
    Join Date
    Nov 2013
    Posts
    9

    Default

    Hi Richard,
    Sorry I have not replied sooner. The reason for the wire between terminal A to the 2nd live, is that I was (probably incorrectly) following the wiring diagram for a basic boiler (see pic) I think I am going to get a Honeywell Evohome Approved guy in to check to make sure that everything is wired correctly. Does anyone know of somebody around Maidstone??

    Thanks

    Nick honeywell.jpg

  7. #17

    Default

    Quote Originally Posted by nickb23 View Post
    Hi Richard,
    Sorry I have not replied sooner. The reason for the wire between terminal A to the 2nd live, is that I was (probably incorrectly) following the wiring diagram for a basic boiler (see pic) I think I am going to get a Honeywell Evohome Approved guy in to check to make sure that everything is wired correctly. Does anyone know of somebody around Maidstone??

    Thanks

    Nick honeywell.jpg
    Ring the 'find an evohome installer' hotline - 01344 656663 - Ask for Lou
    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

  8. #18
    Site Sponsor The EVOHOME Shop's Avatar
    Join Date
    Dec 2014
    Location
    Powys, Mid Wales
    Posts
    479

    Default

    Quote Originally Posted by nickb23 View Post
    Hi Richard,
    Sorry I have not replied sooner. The reason for the wire between terminal A to the 2nd live, is that I was (probably incorrectly) following the wiring diagram for a basic boiler (see pic) I think I am going to get a Honeywell Evohome Approved guy in to check to make sure that everything is wired correctly. Does anyone know of somebody around Maidstone??

    Thanks

    Nick honeywell.jpg
    Hi Nick,

    Well even the diagram above doesn't show two wires on terminal A, only the link wire from the second live terminal with a switched live out of terminal B. evohome wiring (and heating control wiring in general) is relatively straight forward to a heating engineer, so if you are unsure of what you are doing please use an competent heating professional to do fixed wiring.

    Thanks,

    Richard

  9. #19
    Automated Home Jr Member
    Join Date
    Jan 2015
    Posts
    32

    Default

    Quote Originally Posted by nickb23 View Post
    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
    Just a quick note for anybody reading this looking for inspiration for their own installation: Ideally, you shouldn't use a green/yellow sheathed or sleeved conductor as a live.

    I am referring to the link between the 2nd L terminal and the A terminal in the Heating Relay.

    The other lives that are blue, black or grey should ideally be sleeved with brown for identification, too.
    Last edited by thepook; 13th February 2015 at 03:17 PM.

  10. #20
    Automated Home Sr Member
    Join Date
    Oct 2014
    Posts
    84

    Default

    Quote Originally Posted by thepook View Post
    Ideally, you shouldn't use a green/yellow sheathed or sleeved conductor as a live.
    It's not only less than ideal, it's illegal and for damned good reason.

    If someone disassembles, and then reassembles the installation, there's an excellent chance that they'll connect the earth wire to - wait for it - an earth connection. In a perfect world, this will trip an RCD. In the real world, it might accidentally put the metal chassis of whatever it's connected to at a 230V potential.

    Edit:

    BS7671:2008 Regulation 514.4.2

    "The bi-colour combination green-and-yellow shall be used exclusively
    for identification of a protective conductor and this combination shall
    not be used for any other purpose."

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •