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wiring a Lochinvar Knight WHN111 for continuous circulation

roundrightfarm Member Posts: 54
edited April 2018 in Radiant Heating
I've got a Lochinvar installation that has no electric space heating thermostats. The system is controlled by outdoor reset and TRVs on the radiators. I want to wire this for continuous circulation of the Alpha2 pump. One of the programming parameters is "System Pump Type" which allows me to select WWSD (warm weather shutdown) to program the pump to run continuously until outdoor shutdown starts. I'm wondering if I still need to jumper one of the space heating thermostat connections or if I can leave them all unwired?


  • delta T
    delta T Member Posts: 851
    If I remember correctly, you still have to jump out the sh contacts to make the boiler fire. Not sure if the pump in wwsd mode is independant of this though.
  • SuperJ
    SuperJ Member Posts: 605
    I would just wire/plug the Alpha2 to 120v, and put it in summer mode by holding down the mode button. It will exercise the pump automatically occasionally which is good hygiene.
  • keyote
    keyote Member Posts: 659
    you fine adjust the ODR curve until it runs pretty much continuously. then if you ad a tstst it will act as a high limit shutoff in case say a large party or a holiday cooking fest raises temps uncomfortably.
  • JohnNY
    JohnNY Member Posts: 2,688
    You need to close one of the "Heat Loop Demand" terminals to have the boiler when it's out of WWSD.
    Contact John "JohnNY" Cataneo, Master Plumber
    in New York
    in New Jersey
    for Consulting Work
    or take his class.