Results 1 to 3 of 3

Thread: Boiler Heat demand

  1. #1
    Automated Home Lurker
    Join Date
    Oct 2019
    Posts
    4

    Default Boiler Heat demand

    Could someone clarity the operation of heating demand when using evohome on a combi boiler.. Will the evohome controller cycle the boiler defined "under cycle time" if there is no demand, or will a demand for heat have priority regardless of the cycle time?

    Basically will the boiler come on cause there is a demand or by cycle time

    Thanks in advance

  2. #2
    Automated Home Legend
    Join Date
    Sep 2014
    Location
    Scotland
    Posts
    1,826

    Default

    If there is no heat demand the boiler relay will remain off continuously. If there is 100% heat demand the boiler relay will be on continously. In either case the cycle time is not applicable.

    If there is a partial heat demand then the cycle time will be applicable and the heat demand percentage becomes a duty cycle. So for example if it's configured for 6 cycles per hour and the current heat demand is 30%, the cycle period will be 10 minutes, and the relay will be off for the first 7 minutes of each 10 minute cycle and on for the last 3 minutes of each cycle.

  3. #3
    Automated Home Lurker
    Join Date
    Oct 2019
    Posts
    4

    Default

    Quote Originally Posted by DBMandrake View Post
    If there is 100% heat demand the boiler relay will be on continously. In either case the cycle time is not applicable.
    Is this the same operation if one was using opentherm?

    I ask as I originally configured boiler with opentherm but had to use a converter.. at first the boiler seemed to fire up when demand was 100% but I'm sure there was occasions where this wasnt the case. I have now swapped the opentherm with a relay and the boiler fires up alot more, especially when demand is at 100%. It could be that the opentherm/ converter configuration is not working correctly but I was not sure if the correct operation.

Posting Permissions

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