Originally Posted by
timjimbob
I'm mostly concerned about an ICP product but i'm sure all will be similiar.
WHEN hp IS IN DEFROST, WILL DEFROST CYCLE STOP IF CALL FOR HEAT, FROM ROOM STAT, IS SATISFIED? WILL W(HEAT) RELAY, ON DEFROST BOARD, OPEN HEAT CIRCUIT?
There is no one answer. Depends on make and model.
For the ICP you ask about, lets looks at a Heil HCH9 two stage heat pump.
On non−communicating systems, if the thermostat becomes satisfied (Y1 or Y1 and Y2) before the defrost cycle is terminated, the control will “hold” in defrost mode and finish the defrost cycle on the next call for heat.
On models with communicating systems, a defrost "hold" is not needed because the system will complete the defrost cycle before shutting down the system.
As a general rule on most older heat pumps, the unit will shut off when the call for heat is satisfied, and the defrost cycle will continue on the next call for heat.
Instead of learning the tricks of the trade, learn the trade.