Your heat pump should go into defrost. If it's not, something's wrong and needs to be checked out. It should not ice over; that's what defrost prevents. I believe the technician should have been able to initiate a defrost cycle manually...

I will contact the technician asking just that and I will keep you posted on the developments. The heat pump is useless right now. It doesn't generate heat at all, so that all the air that goes through it into the house is a draft of air from outside.

If you desperately need heat, your system should have electric heat strips (emergency heat), but this can get expensive. The heat pump iced up is indeed useless because the outdoor coil is what transfers heat.

You'll want to inquire if they tested the defrost cycle while at your house as this is an essential aspect of the heat pump. What is the make/model of your heat pump? Should be a way to manually initiate defrost on the defrost board.

Keep us posted.

The heat pump is useless right now. It doesn't generate heat at all, so that all the air that goes through it into the house is a draft of air from outside.Unless your HVAC system has a provision to bring in outside air for ventilation, there shouldn't be any way for a "draft of air from outside" to get inside the house through it. That's like my grandmother believing that her window unit sucks hot air (and dust) from outside, cools it, then blows it into the house.

Heat_Pump, is this your first experience with your name-sake system? It's normal for the outside condenser unit to get icy during some weather conditions. When running in heating mode, the outside part functions as a cooling coil to pick up heat from outside and "pump" it inside (there's heat in air technically down to absolute zero, 0°K or -273°C or -459°F). In the same way that a food freezer gets frosty, so does the heat pump. And same as a refrigerator or freezer needs periodic defrosting, so does the heat pump .. which it will do automatically (unless there's something wrong with it). Typically every 60 to 90 minutes a circuit board checks temperature sensors on the coil to determine if defrosting is needed. Defrosting is performed by switching the system back to air conditioning mode for about 10 mins so the outside coil heats up and the frost melts off. During defrost the auxiliary electric heat strips activate to counteract the cold (air conditioned) air that would otherwise be blowing inside the house. If your heat strips are not working, then it will blow cold air during defrost.

In some cases such as water dripping from the roof onto the unit, a layer of ice, icicles, etc., can develop on the fan blade. The unit should be protected by a gutter to help prevent that from happening, but sometimes it's unavoidable such as during freezing rain.

If the compressor fails completely or the unit isn't defrosting properly then you can manually switch the thermostat to "Emergency Heat" which shuts off the compressor and runs only the electric heat strips. If your unit looks like these pictures, then you need to run in Emergency mode.

Great post and pictures, dadoes.

Thank you everyone. The comments and photographs were indeed quite informative. I managed to squirt some oil on the fan shaft, which was stuck in gunk. The heat pump started working, but it is still pumping in air that is a few degrees too low for comfort.

So is the defrost mechanism working?

The temperature is not yet low enough for me to make this determination. I will keep you posted on this.

I am curious what model and age this unit is. If the temp is still above freezing it should still be producing pretty decent register temps in my opinion. Not compared to a gas unit but outlet temps above 80. Every setup is different but I can get high 80 to low 90 degree outlet temps at around freezing. This is with a 13 seer Tempstar with no bells and whistles.

I just checked my vents 88 degrees at the register its 33 outside with light snow and the units fins are just starting to frost. I think I could be a lot better with a txv and a 15seer carrier or the like.

It is icing up when it is heating, so I believe that the defroster is not working. The fan is not working either. I wonder if it would deteriorate, for instance rust away, if left idle during the winter.

Not good for your compressor or heating bill to let it run like that. Heat pumps shouldn't really ice up at all. They will accumulate frost that the defrost cycle takes care of. You say the fan's not working. In defrost, the fan will stop, so your defrost system may just not be operating correctly for whatever reason. Best bet is to call that company (or perhaps another company) back to take a look. Good luck.