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boiler keeps coming on and off

i am having problem with my zone thermostat's (3) , they sometime keep cycling the boiler on and off . in the boiler
room i can hear clicking ( signal for the boiler to cycle)
what causes this


  • John McArthur_2
    John McArthur_2 Member Posts: 157

    It can be caused by a poor connection or a faulty relay coil.

    It would help to have a bit more informations, such as type of control and thermostats.

    Have you attempted to isolate the boiler from the thermostats to identify where the problem lies? If you are using a zone control relay such as a Taco SR503 you can remove the thermostat connections and install a jumper wire to test the relay contacts.

    Good luck.
  • Anthony Menafro
    Anthony Menafro Member Posts: 188

    Have you checked the anticipator on the T-stat? Most times that's your culprit.

This discussion has been closed.