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Thread: Opentherm Boiler control Add Hot water

  1. #1
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    Default Opentherm Boiler control Add Hot water

    I have an intergas boiler heat only with opentherm boiler control

    I now want to add Stored Hot Water I have the Hot Water Kit is it jus a matter of adding it under system devices I have a new MV on the Hot water circuit and will wire this to the BDR from Heating Kit


    Thanks
    mylesm

  2. #2
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    Quote Originally Posted by mylesm View Post
    I have an intergas boiler heat only with opentherm boiler control

    I now want to add Stored Hot Water I have the Hot Water Kit is it jus a matter of adding it under system devices I have a new MV on the Hot water circuit and will wire this to the BDR from Heating Kit


    Thanks
    mylesm
    When I set up my Evohome for Opentherm use, the HW kit was bound under STORED HOT WATER; that is, a CS92A bound to BDR, and BDR bound to Evohome. I cannot speak for Intergas boilers but the Atag needs to receive feedback that there is a hot water demand. Normally this is via a diverter valve. In my case, I have the standard motorised HW zone valve and an inline open motorised valve that closes whenever the HW zone valve opens. The risk of getting this set up wrong is, with some boilers, that when Opentherm demands 90C for HW re-heating the boiler flow temperature will shoot off in this direction. With my set up, the boiler itself limits the max boiler temperature for HW re-heating to 70C - irrespective of what Opentherm demands - as set in the boiler profile. If I recall, the Viessmann 100 is something of a 'bad boy' in this respect.

  3. #3
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    Quote Originally Posted by HenGus View Post
    When I set up my Evohome for Opentherm use, the HW kit was bound under STORED HOT WATER; that is, a CS92A bound to BDR, and BDR bound to Evohome. I cannot speak for Intergas boilers but the Atag needs to receive feedback that there is a hot water demand. Normally this is via a diverter valve. In my case, I have the standard motorised HW zone valve and an inline open motorised valve that closes whenever the HW zone valve opens. The risk of getting this set up wrong is, with some boilers, that when Opentherm demands 90C for HW re-heating the boiler flow temperature will shoot off in this direction. With my set up, the boiler itself limits the max boiler temperature for HW re-heating to 70C - irrespective of what Opentherm demands - as set in the boiler profile. If I recall, the Viessmann 100 is something of a 'bad boy' in this respect.
    Thanks for that my Boiler is already in service as a heat only and I now want to add Stored HW so I will just try to add it and see how I go

  4. #4
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    My Vaillant, heat only, was previously only doing the CH via Evohome. So adding the HW Water kit was a simple case of adding a Stored HW device and wiring up the BDR to open the MV rather than the old time clock. Infact my BDR for the KW just replaced the Honeywell time clock because all the necessary wiring was already there. My CH MV is wiring to open with the pump i.e. always open.

  5. #5
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    Quote Originally Posted by bruce_miranda View Post
    My Vaillant, heat only, was previously only doing the CH via Evohome. So adding the HW Water kit was a simple case of adding a Stored HW device and wiring up the BDR to open the MV rather than the old time clock. Infact my BDR for the KW just replaced the Honeywell time clock because all the necessary wiring was already there. My CH MV is wiring to open with the pump i.e. always open.
    Great thats what I was hoping so will install this weekend

  6. #6
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    Quote Originally Posted by bruce_miranda View Post
    My Vaillant, heat only, was previously only doing the CH via Evohome. So adding the HW Water kit was a simple case of adding a Stored HW device and wiring up the BDR to open the MV rather than the old time clock. Infact my BDR for the KW just replaced the Honeywell time clock because all the necessary wiring was already there. My CH MV is wiring to open with the pump i.e. always open.
    I installed HW Kit Last weekend and as you said a simple matter of adding it Under System Devices by Enabling Stored Hot Water and then wired BDR to MV and all is good

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