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help with making DHW pump priority

Hello I am trying to use make use of my current setup while making my Domestic hot water priority. I want to shut off my heat zone circ until the dhw zone is satisfied. I have also attached a schematic to show current wiring set up. I do have a RIB 2401 relay and also a honeywell R8845U switching relay sitting on my spare parts shelf not being used. I have a erie zone control that has 3 zone circs i am only concerned with shutting down one zone when domestic water is being called for. My domestic water is controlled by my gas viessmann boiler controller. When the sensor detects water below 50 degrees C it will kick the pump on to heat the water, I then want the heat zone to turn off to recover the dhw tank faster and then when the domestic hot water pump turns off let the zone begin heating again if calling for heat. Any suggestions or ideas would be great. thank you!imageimageimageimage


  • JStar
    JStar Member Posts: 2,752
    Do yourself a HUGE favor and buy a zone-control board with built in priority for DHW.
  • Robert O'Connor_12
    Robert O'Connor_12 Member Posts: 728
    Which boiler is it?
    The answer may be right in Viessmann install instructions.
  • rsv101
    rsv101 Member Posts: 14
    Viessmann VBC 22 with a Trimatik MC controller. The other part of the equation is that I have an outdoor wood boiler. The gas never kicks in. The controller just tells the dhw pump to come on or off. I have looked through the viessmann books and could find no way to program it. I have a zone control board with priority but it is for 3 zones. The previous home owner hooked three different heating zones to it and left the domestic hot water on the viessman control. So basically the viessmann boiler only supplies my hot water when not burning wood and telling my pump for dhw to turn on and off.