Defrost cycle generates frigid air

by Mark
(Massachusetts)

I have 1 year old Bryant Extreme 2 ton. When first installed there were no heat strips. This issue has been occurring since day 1. In defrost mode the air coming from my vents was consistently in the 30’s, a couple of times in the 20’s. Room temperature would sometimes drop as system cycled between defrost and non-defrost, and heat couldn’t keep up. Heat strips were added and now my minimum air temperature is in the 50’s. So the heat strips are just masking the problem by heating the 30 degree air to 50.

I’ve also measured the temperature on the exterior of the refrigerant line coming from the condenser outside to the air handler inside. At a point just before the line enters the air handler the temperature is the same as what I saw with the vent air prior to the heat strips – consistently in the 30’s sometimes in the 20’s.

So it looks like in defrost mode the heat pump thinks it’s supposed to provide me with frigid refrigerant and air. I can’t imagine that as designed and when properly installed this is what it’s supposed to do. Any ideas on what might be wrong would be very much appreciated.

Thank You.