Page 4 of 4 FirstFirst 1234
Results 31 to 36 of 36

Thread: Opentherm with Evohome

  1. #31
    Automated Home Legend
    Join Date
    Jul 2014
    Posts
    1,001

    Default

    Would be keen to know what the Intergas issue is. Who in the world would invest in Evohome and run a single zone!

  2. #32
    Automated Home Legend top brake's Avatar
    Join Date
    Feb 2015
    Location
    the edge of the cloud
    Posts
    827

    Default

    Quote Originally Posted by HenGus View Post
    I have at last found an ecotechnician that is keen to work with me to provide an Opentherm solution with an Atag boiler. That said, I am struggling with a couple of things which are the costs/benefits of a 250 additional cost for an EBus to Opentherm converter and Opentherm bridge, and getting confirmation that the Atag Opentherm connection can cope with multiple HR92 zones? FWiW, I finally got confirmation from the guys at Intergas that their boilers do have an issue which is under investigation in The Netherlands.
    ATAG is OT so no adapter needed, just wire OpenTherm Bridge
    ATAG supports multizoning with evohome

    thanks
    I work for Resideo, posts are personal and my own views.

  3. #33
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,828

    Default

    Quote Originally Posted by HenGus View Post
    and getting confirmation that the Atag Opentherm connection can cope with multiple HR92 zones?
    I can't see how the number of HR92 zones could be an issue - the boiler is not aware of how many zones there are.

    The heat demand of the different zones is aggregated by the Evotouch controller and one flow temperature is chosen (at a given moment in time) to meet the demand and sent via OpenTherm to the boiler. Whether this is one HR92 zone or 10 is irrelevant to this process.

  4. #34
    Automated Home Legend paulockenden's Avatar
    Join Date
    Apr 2015
    Location
    South Coast
    Posts
    1,594

    Default

    Perhaps someone mentioned the "Single Zone Thermostat", and things got confused?

    P.

  5. #35
    Automated Home Legend
    Join Date
    May 2014
    Posts
    988

    Default

    Quote Originally Posted by top brake View Post
    ATAG is OT so no adapter needed, just wire OpenTherm Bridge
    ATAG supports multizoning with evohome

    thanks
    Atag Technical Support would beg to disagree:

    Quote: With the Honeywell Evohome system there needs to be a Honeywell OpenTherm bridge that connects to our OpenTherm blue bus connection. That is the only controls connection to the boiler. A blue bus connector needs to be ordered from us by your Atag installer, part number S4745000 for an external third party control to connect with our boiler. Unquote

    edit:

    Both TopBrake and Atag are correct (apologies TB). It would appear that Evohome O/T Bridge does connect to what Atag calls a Blue Bus but it requires a simple connector/ adapter.
    Last edited by HenGus; 28th October 2016 at 10:06 PM. Reason: Add to info

  6. #36
    Automated Home Legend
    Join Date
    May 2014
    Posts
    988

    Default

    Quote Originally Posted by DBMandrake View Post
    I can't see how the number of HR92 zones could be an issue - the boiler is not aware of how many zones there are.

    The heat demand of the different zones is aggregated by the Evotouch controller and one flow temperature is chosen (at a given moment in time) to meet the demand and sent via OpenTherm to the boiler. Whether this is one HR92 zone or 10 is irrelevant to this process.
    This was the response that I got from an eco technician/installer (well known to TB - I suspect):

    The problem is that the boiler or Evohome (no one really knows which at the moment) doesn't cope with modulating the setpoint with multiple zones.

    My theory is that there is too much data and the boiler PCB can't interact quickly enough with the OpenTherm bridge so it drops its knickers and runs at whatever the maximum setting is.


    Read more: http://www.diynot.com/diy/threads/in...#ixzz4ONroCcTm

    The problem is also reported on The Evohome Shop Forum. Intergas Technical Support confirmed to me over the phone that there is a known issue with the handling of multiple zones and they had no idea when a fix would be rolled out; however, they acknowledged (as they have had a visit I suspect from TB) that the Honeywell O/T Bridge will connect to their boilers.

Posting Permissions

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