2 stage Thermostat Function

johntrhodes81

Hello,

I am new here but tried searching and didn't find anything.

I am working on the integration of a hydronic and forced air system and have a question about the function of 2 stage (2H/2C) thermostats.

When the thermostat calls for stage 2 heat or cool (W2 or Y2) are the stage 1 terminals (W1 or Y1) still energized?
Or does it depend on brand of thermostat?

Trying to determine if I need to plan on additional relay logic to energize stage 1 when stage 2 is energized.

Thanks,
John R.

bob_46

I hesitate to make a blanket statement but in my experience the first stage stays closed when the second stage closes .

johntrhodes81

Thanks.