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I purchased a Honeywell RTH6580WF to use with my recently installed Triangle Tube Prestige Solo 110 propane boiler. I only have two wires at my existing heat-only thermostat. I understand that the c-wire is common. There is no terminal labeled "C" in the boiler, but all the grounds are to the chassis/terminal block backplane.
The existing connections at the thermostat are
RH and a jumper between
RC. I contacted Honeywell customer service, and they said "call a contractor." Can I power the RTH6580WF by simply connecting the
C in the new thermostat to household common, or do I need to run it back to the chassis or somewhere else of the boiler, or...? If I HAVE to add a separate transformer, where do I connect the + and - from the transformer to the thermostat?