New Goodman AVPTC and hydronic heat wiring for heat

stoker420

Hello, I searched the topics and could not find an answer to my situation.

I installed a AVPTC air handler with communication CTK04 thermostat and I need to connect my old hydronic oil fired boiler. And I'm not sure how to wire it. My old system had a hydrostat at the exchanger and one on the boiler, attaching pics. I see in my board I have connections for an electric heat W1 and aux W2 when I call for heat I get 24 v across W1 and C, I need to turn that into a signal for my boiler to activate. How should I wire it? Should I upgrade the control unit on the boiler. I eventually will be installing geothermal and bought this unit to get me through the next 5 years or so. My old unit had to be replaced after 26 years. I can't afford electric heat here in New England and don't have space in my panel for another circuit anyway.

stoker420

P.s. it's not a heat pump it's a 2 stage communication ac unit outside.

Jamie Hall

You can — and should — leave the aquastat on the boiler alone. That control turns the boiler itself on and off in response to the circulating boiler water temperature.

Now. The next question is — what on the system transfers heat from the boiler to whatever transfers it into your house? The old system. Figure out what that is. Then use the W1 and C connections, which provide (you say) 24 VAC power, to activate a relay. The dry normally open contacts of that relay can be wired in place of — or in parallel with — whatever old thermostat controlled the old system.

HVACNUT

Wiring diagram for the air handler?

No separate relay board needed for hydro coil?