Outside compressor is frozen solid

[MustISO]

We have a two zone HVAC. When I came home today one compressor was frozen solid and there's a hissing noise coming from the inside of the unit. There is ice everywhere but the fan is still turning.

It seems like the heat is still working on each floor, so I'm not sure what happened. Does that only affect cooling? What needs to be done?

 

[IceBergSLiM]

call the manufacture support line?

 

[Vette73]

I woudl turn it off. Sounds like the defrost mode is not working. You can damage it if you keep running ti like that if that has not already happened.

Now you have heat pumps right? that is what my replay is for. If not you have other problems.

 

[Fiat1]

Do you have gas or electric heat?
From the sounds of things you AC compressor went bad or developed a leak.
They can replace the compressor if its that or repair a leak if it is in a pipe.

 

[MustISO]

We have gas heat on the lower levels and heatpump on the top floor. One unit is basically just a fan with a motor and the other has what looks like a canister and much more pipe than the other. A neighbor said that's the heatpump. The heat pump has something called Aux Heat and it's still putting out warm air. Guess it's going to be an interesting night.

 

[Rubycon]

The evaporator is iced up. Your best bet is to call the contractor. Your defrost cycle is not working correctly. Sometimes severe climates can overwhelm the defrost cycle's ability to remove buildup of ice on the evaporator.

The defrost cycle actually runs in A/C mode making the outdoor coil a condenser. The outdoor fan will be shut off during this cycle causing head pressure to rise and generating lots of heat to melt the ice. If the ice is very thick this amount of heat for the cycle duration may not completely remove it and it will just get heavier as the water near the coil re-freezes when the cycle is terminated. Without airflow around the evaporator suction pressure plummets. Your auxiliary heat will run a lot too.

What the average user can do is switch the thermostat to cooling so the reversing valve engages. The outdoor fan will run but with ice over the coil the flow through the coil is still nil. It will melt off. Running the unit iced for extended periods of time is bad because if there is enough liquid to fill the suction accumulator to the top you run the risk of liquid slugging the compressor which can do costly damage to the valves!

 

[MustISO]

I just talked to someone who's done work for us before. He said to use the heating system as little as possible and set the thermostat to Emg. Heat. Hopefully we can get it fixed tomorrow, it's going to be VERY cold.