frozen ac/heat pump question.

[keith ouellette]

Does my outer unit being covered with ice keep it from working properly. I have never paid attention to my heater before.
If it is set to 69 it runs non stop and won't turn off.
Is that because of the ice? Its already frozen solid at 6:30

I tried switching it to emergency heat, which as far as I can figure is a way to turn on the heating coil in the blower unit but is does not seem to be working very well either.

[Mike Henderson]

If your outside unit is frozen solid, you won't get much heat in the house. I thought all heat pumps had a resistance coil which is activated when the temperature outside goes below some value.

You could try hosing off the outside unit to melt the ice, but if it's cold outside that would only work for a short while and then it'd ice up again.

Mike

[Dan Mitchell]

Your heat pump should have a function whereby it basically runs in AC mode briefly, warming the outer coils periodically (as is the case when you run it as an air conditioner, outside coils get hot, inside coils get cold) to deice them. Sounds like some aspect of the system that regulates that is on the fritz. I know that my heat pump has a resistive heat section for supplemental use when it is too cold outside for the heat pump to be efficient. The resistive elements are WAY more expensive to operate, however.

Dan

[keith ouellette]

If there is something thats supposed to thaw the outer unit isn't working or no one ever thought it would be so necessary in central florida and the coil heater in the blower unit only goes on if I do it manually.

I guess I need to have it looked at.

[Robert Parrish]

Keith, My next door neighbor is having the same problem, his coils are freezing up. Mine are not, the defrost cycle kicks on every so often to clear the ice off. When it defrosts it will blow cold air for a couple of minutes. I had a service guy out a few days ago because I wasn't getting much heat when the outside temp was below 45. The problem was that my programmable thermostat was not programmed for aux heat. I'm on the South West coast of Florida and this is the coldest I have ever seen.

[Dave Ogren]

Dan is completely right about going into a cool mode even in the winter to thaw the frozen coils. It is a reversing valve that reverses the system and melts the ice off, then is ready to go again. There is a timer that controls it, it is adjustable, under the outside H.P. cover. I had to adjust mine to defrost every 60 minutes. They start to dramatically loose efficiency at about 32 degrees F. I do not have the supplemental heat coils built into the inside heat exchanger, costs too much to run.
Good Luck warmer weather comming next week.

Dave

[Joe Pelonio]

I had that problem on one in my shop a few years ago, and it turned out that the "supplemental" heat coil had died. That was supposed to not only melt the frozen condensation coils, but provide some warm air inside during the process.

According to the repairman, that year's sustained sub-freezing weather and the fact that I kept it off at night caused it to run constantly and burned it out. Heat pumps are not meant for really cold winter climates and do have trouble keeping up.

[Bill Cunningham]

most usually have a reversing valve that kicks the HP into AC mode until the coils thaw out. During the AC mode, your Auxiliary heat source usually takes the chill off the coil inside. Once thawed, the reversing valve kicks back into heat mode and away you go again..