From S-Plan to Boiler Relay

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • mpkaye
    Automated Home Lurker
    • May 2015
    • 3

    From S-Plan to Boiler Relay

    New self-install Evohome user here. Our system is a Honeywell S-Plan with HTG and DHW 2-way zone valves, oil boiler and (obviously) pump. I have wired exactly as per S-Plan diagram (Figure 9) in the installation guide. However, I am finding short cycling a problem so I would like to switch to a boiler relay system.

    We have 14 radiators in total, 10 zones comprised of 12 HR92s, 1 manual TRV set to off, and a towel radiator with manual valves (partially open). The boiler is a 17 year old oil fired Camray 3, doesn't require pump overrun. No bypass valve.

    I would like to validate my wiring plan. As I understand it, to switch to boiler relay I need to do the following:

    1. Electrically disconnect the HTG zone valve completely and latch open on the lever.
    2. Remove the DHW zone valve end switch connection (orange wire).
    3. Wire current HTG BDR91 terminal B to pump and boiler live (terminal 10).
    4. Hard reset and unbind all system components and setup from scratch with boiler relay.
    5. Pay attention to Cycle Rate and Minimum On Time parameters.

    Am I right in thinking these are the actions necessary to move from S-Plan to boiler relay and so gain some control over boiler firing?
  • mpkaye
    Automated Home Lurker
    • May 2015
    • 3

    #2
    Me again

    I went ahead with the changes and all seems well so far. One thing I have noticed is that when rebinding HR92s sometimes, on the initial bind, they behave as if they were in a multi-actuator zone (i.e. as if you were adding a second HR92 so you get the press bing on all actuator's message...) Whenever I got that, I deleted the zone and started again. Why is this? Is it a bug?

    Comment

    • The EVOHOME Shop
      Site Sponsor
      • Dec 2014
      • 483

      #3
      Originally posted by mpkaye View Post
      Me again

      I went ahead with the changes and all seems well so far. One thing I have noticed is that when rebinding HR92s sometimes, on the initial bind, they behave as if they were in a multi-actuator zone (i.e. as if you were adding a second HR92 so you get the press bing on all actuator's message...) Whenever I got that, I deleted the zone and started again. Why is this? Is it a bug?
      The 'actuator' problem when binding the HR92's means you rushed the binding sequence (pressed the green tick on the evohome Controller before 'sync' had shown on the HR92) and basically the binding had crashed due to lack of time. Remember the system is 2 way comms and this isn't done in a split second. Just take your time when binding HR92's (leave 3-5 seconds after pressing the bind button on HR92 before pressing the green tick) and this problem will not occur and you will be greeted with the correct sequence of events (i.e. 'do you want to add more HR92's to the same zone' question).

      Hope that helps,

      Richard

      Comment

      • Chicleracha
        Automated Home Lurker
        • Nov 2015
        • 3

        #4
        Originally posted by mpkaye View Post
        New self-install Evohome user here. Our system is a Honeywell S-Plan with HTG and DHW 2-way zone valves, oil boiler and (obviously) pump. I have wired exactly as per S-Plan diagram (Figure 9) in the installation guide. However, I am finding short cycling a problem so I would like to switch to a boiler relay system.

        We have 14 radiators in total, 10 zones comprised of 12 HR92s, 1 manual TRV set to off, and a towel radiator with manual valves (partially open). The boiler is a 17 year old oil fired Camray 3, doesn't require pump overrun. No bypass valve.

        I would like to validate my wiring plan. As I understand it, to switch to boiler relay I need to do the following:

        1. Electrically disconnect the HTG zone valve completely and latch open on the lever.
        2. Remove the DHW zone valve end switch connection (orange wire).
        3. Wire current HTG BDR91 terminal B to pump and boiler live (terminal 10).
        4. Hard reset and unbind all system components and setup from scratch with boiler relay.
        5. Pay attention to Cycle Rate and Minimum On Time parameters.

        Am I right in thinking these are the actions necessary to move from S-Plan to boiler relay and so gain some control over boiler firing?
        Very similar situation here, where would you connect terminal A on the BDR91?

        Comment

        • Fursty Ferret
          Automated Home Sr Member
          • Oct 2014
          • 84

          #5
          To live (link the second L and A).

          I've also done the above, works fine.

          Comment

          • Chicleracha
            Automated Home Lurker
            • Nov 2015
            • 3

            #6
            Originally posted by Fursty Ferret View Post
            To live (link the second L and A).

            I've also done the above, works fine.
            NEW DIAGRAM COMBI IDEAL LOGIC.jpg

            thanks so much @Fursty Ferret, did i get it right?

            Comment

            Working...
            X