Installing a Evohome System

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • top brake
    Automated Home Legend
    • Feb 2015
    • 837

    #16
    Originally posted by tom2806 View Post
    but if the thermostat is battery powered it surely will not have 230v mains to it

    not true

    heating system wiring to /from thermostat can be 230v, 24v or potential free

    please take care
    I work for Resideo, posts are personal and my own views.

    Comment

    • tom2806
      Automated Home Jr Member
      • Feb 2015
      • 18

      #17
      Well its new build property so this is the only thermostat that has been installed. what power would the switching wire carry?

      Comment

      • SensibleHeatUK
        Moderator
        • Feb 2009
        • 228

        #18
        There is no way of knowing what voltage the stat uses as that is entirely dependent on the boiler. Most use a 230v signal, so it could be mains, others can be low voltage. If it is only a 2-core cable you will not be able to use it in any case as the BDR needs a minimum of three cores (4 cores if the boiler switching is low voltage). I will echo that if you are not aware of these basic electrical issues I would leave it to an electrician to fit it for you, 230v electrics need to be left to those that are competent and experienced. You could then have the BDR installed near the boiler and connected to the existing boiler wiring centre (or direct to the boiler if it is a combi). Then it only needs the existing stat cable to be disconnected/made safe, and you can either leave the redundant room stat on the wall, or remove it and make good.
        Sensible Heat
        SensibleHeat.co.uk

        Comment

        • The EVOHOME Shop
          Site Sponsor
          • Dec 2014
          • 483

          #19
          Originally posted by tom2806 View Post
          Well its new build property so this is the only thermostat that has been installed. what power would the switching wire carry?
          The majority of heating thermostats (battery operated or not) are switching 230v. An approved voltage tester would quickly and safely confirm this though. I echo the other guys, if you are needing to ask lots of installation questions with regards to the heating installation, I suggest getting an installer to help you.

          From my experience the recommendation of an 'electrician' to do the works might not be the best step. Electricians are fine with wiring but the majority have very limited knowledge about G3 Regs (Unvented Cylinders), are not normally Gas Safe or OFTEC registered (so not insured to work on boilers) and have limited knowledge on what heating components are or what they do.

          For example, I had an electrician contact me the other day and after a brief chat about the evohome installation he was doing for a customer we had supplied the equipment to, I found out straight away that he had already removed all the manufacturers safety controls from an unvented cylinder and wired both BDR91's right next to each other right next to the cylinder!

          So be very wary of who you employ - experience and knowledge is vital!

          Comment

          • tom2806
            Automated Home Jr Member
            • Feb 2015
            • 18

            #20
            Originally posted by The EVOHOME Shop View Post
            The majority of heating thermostats (battery operated or not) are switching 230v. An approved voltage tester would quickly and safely confirm this though. I echo the other guys, if you are needing to ask lots of installation questions with regards to the heating installation, I suggest getting an installer to help you.

            From my experience the recommendation of an 'electrician' to do the works might not be the best step. Electricians are fine with wiring but the majority have very limited knowledge about G3 Regs (Unvented Cylinders), are not normally Gas Safe or OFTEC registered (so not insured to work on boilers) and have limited knowledge on what heating components are or what they do.

            For example, I had an electrician contact me the other day and after a brief chat about the evohome installation he was doing for a customer we had supplied the equipment to, I found out straight away that he had already removed all the manufacturers safety controls from an unvented cylinder and wired both BDR91's right next to each other right next to the cylinder!

            So be very wary of who you employ - experience and knowledge is vital!
            Hey

            I ill demo take all this into consideration.

            one quick question, I have 2 zone valves controlling the 2 separate zones in the house (ground floor and then middle + Top). If I want to install the HR92 TRV then can I just set the zone valves to manuel. Will this mean they are constantly open and the heating is now done at room level on the evohome trove?

            Cheers

            Comment

            • The EVOHOME Shop
              Site Sponsor
              • Dec 2014
              • 483

              #21
              Originally posted by tom2806 View Post
              one quick question, I have 2 zone valves controlling the 2 separate zones in the house (ground floor and then middle + Top). If I want to install the HR92 TRV then can I just set the zone valves to manuel. Will this mean they are constantly open and the heating is now done at room level on the evohome trove?
              If the 2 port heating motorised zone valves are completely electrically disconnected and left in the manually open position with HR92's on all radiators, then the HR92's will be acting as the heating zone valves. This IMO is best practice when using evohome.

              Comment

              • jonstatt
                Automated Home Guru
                • Feb 2015
                • 111

                #22
                Originally posted by The EVOHOME Shop View Post
                If the 2 port heating motorised zone valves are completely electrically disconnected and left in the manually open position with HR92's on all radiators, then the HR92's will be acting as the heating zone valves. This IMO is best practice when using evohome.
                I am curious on this. Why is this better if you already have a bypass loop in place for pump over-run? Imagine it's a warm day and all HR92s are therefore off. If the heating valve is permanently open, then when you are heating water, you are also heating up the CH loop that goes right around the house.....okay, you wont be heating any radiators but on a large house this will still require measurable energy. In Tom's situation, with both zone valves permanently open, when heating is needed, if only one radiator is required, you would be heating up both zones loops instead of just the one that the radiator requires. Why not keep the zone valves, and have two BDP91s?
                Last edited by jonstatt; 22 February 2015, 11:31 AM.

                Comment

                • tom2806
                  Automated Home Jr Member
                  • Feb 2015
                  • 18

                  #23
                  I'm pretty sure this won't be the case with heating water as I am on a combi boiler and so hot water is instant and the rad pipe work won't call for any water

                  Is this correct?

                  Comment

                  • tom2806
                    Automated Home Jr Member
                    • Feb 2015
                    • 18

                    #24
                    Hi

                    So I've had someone round to check if there is mains power to the thermostat. They have confirmed that there is as its mains power switching. What they cannot get there head round is the wiring for the BDR91 relay.

                    The below is the current setup on the thermostat:

                    IMG_0411.jpg

                    The brown wire is carrying the mains power down which then switches on the black wire.

                    The thing that baffles is why they used 4 core cable for this. Can anyone suggest how to wire the BDR91 from this setup.

                    Cheers
                    Attached Files
                    Last edited by tom2806; 22 February 2015, 09:27 PM. Reason: photo was upside down and it still is

                    Comment

                    • top brake
                      Automated Home Legend
                      • Feb 2015
                      • 837

                      #25
                      Originally posted by tom2806 View Post
                      Hi

                      So I've had someone round to check if there is mains power to the thermostat. They have confirmed that there is as its mains power switching. What they cannot get there head round is the wiring for the BDR91 relay.

                      The below is the current setup on the thermostat:

                      [ATTACH=CONFIG]487[/ATTACH]

                      The brown wire is carrying the mains power down which then switches on the black wire.

                      The thing that baffles is why they used 4 core cable for this. Can anyone suggest how to wire the BDR91 from this setup.

                      Cheers
                      Recommend that you engage the services of a heating engineer familiar with wireless controls to install the BDR91 according to the wiring diagram in the evohome installation manual
                      I work for Resideo, posts are personal and my own views.

                      Comment

                      • sharpener
                        Automated Home Sr Member
                        • Jan 2015
                        • 78

                        #26
                        Originally posted by tom2806 View Post
                        The thing that baffles is why they used 4 core cable for this. Can anyone suggest how to wire the BDR91 from this setup.
                        Maybe the four core cable was put in at the first fix stage before they knew what controls would be fitted?

                        The good news is that it probably means you can install in place of the existing thermostat either the BRD91 or the receiver for a wireless thermostat somewhere else as per my earlier posting. The bad news is that as top brake says you will have to spend money employing someone who knows what they are doing.
                        Last edited by sharpener; 22 February 2015, 11:02 PM.

                        Comment

                        • tom2806
                          Automated Home Jr Member
                          • Feb 2015
                          • 18

                          #27
                          Honeywell dont make the wiring diagram the simplest thing to Understand. Probay translated from German badly.

                          Comment

                          • top brake
                            Automated Home Legend
                            • Feb 2015
                            • 837

                            #28
                            Originally posted by tom2806 View Post
                            Honeywell dont make the wiring diagram the simplest thing to Understand. Probay translated from German badly.
                            Basically it is a permanent live and neutral
                            Then link the live across to the terminal A if you need mains switching

                            A connects to B when the relay is energised

                            It doesn't get much simpler

                            In your installation your installer will need to find the other end of the wires and connect them up as required

                            Any electrician that is experienced in heating system wiring will have no problem reading it, tens of thousands of these type of devices are sold and installed every year

                            Bear in mind that this equipment is primarily designed for the professional trade installer
                            Last edited by top brake; 22 February 2015, 11:57 PM.
                            I work for Resideo, posts are personal and my own views.

                            Comment

                            • Wallyİ
                              Automated Home Sr Member
                              • Jan 2015
                              • 53

                              #29
                              It should be relatively easy from the looks of it...

                              Just follow the wires to the fuse box of your boiler system...(You can also do this while measuring the voltage on the wires while the old thermostat is in on-mode)

                              These wires almost certainly operate your circulation pump...

                              Once found disconnect your old thermostat and with the entire system disengaged from the grid connect wires to the A (brown) + B (black) slots in the relay...

                              Connect the power supply wires to the N (blue) and L (brown) slots...

                              Engage the fuse box and test everything...

                              (best to use a 4 or 5 wire cable that goes from your fusebox to the relay for power and relay)
                              Last edited by Wallyİ; 23 February 2015, 12:13 AM.

                              Comment

                              • tom2806
                                Automated Home Jr Member
                                • Feb 2015
                                • 18

                                #30
                                I'm believe they would operate my pump but will go via the already installed zone valves allowing then to engage and then the boiler is called from a switch on the zone vAlve. If the zone valves are set to always open then the power will go straight to the boiler pump.

                                I'm just wondering what the grey cable is in the picture. Not actually connected to anything

                                Comment

                                Working...
                                X