1

I am having trouble installing a new wireless thermostat to my existing Weil McLain boiler. My existing control wire utilized an Rh and W on the thermostat, but utilized the Y and G terminals on the boiler itself. The installation manuals indicate I need to connect a new C-Wire from the C terminal from the boiler to their c terminal on the thermostat and reconnect the other wires as is, but that doesn’t work. Do I need to relocate the wire on the Y terminal to the R terminal or am I missing something else? enter image description here

  • Is the LWCO allowing the boiler to fire? If the low-water cutoff has tripped, then the whole system will appear shut down because the thermostat terminals are downstream of the LWCO – ThreePhaseEel Feb 4 at 3:49
  • Or, in other words, can you measure 24VAC between G and C? – ThreePhaseEel Feb 4 at 4:21

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.