Frytown wrote:What tells the circulator to kick on?
Your triplestat does it automatically when a call for Heat from the wall stat is made.
Remember, AA Boiler would be controlled from stat threw 1st stage compressor Y terminal screw.
You don't need any circulation when your using forced air propane furnace this is Emergency/Aux Mode...1st stage is locked out from stat.
The AA boiler will continue to Hold A Fire w/ timer, though...unless you switch off the whole boiler.
The real question is, What turns the fan on? Answer is the Green Wire...Boiler never sees it...it see the 1st stage wire Y...fan G will be switched automatically by stat to FA Furnace at same time 1st stage Y comes on to boiler.
AA Boiler gets only 2/ wires...Y and C to a 24 volt single pole isolation relay wired to it's coil...normally open contact of relay has 2/wires to 8124 aquastat (T.T.) to call for boiler heat.
FA Furnace gets 4/ wires R, AUX/E, G and C, which C is shared w/ both boiler and furnace.
Do you have 5/ wires now at stat?
You never mentioned air conditioning???