Auxiliary Heat

[cujok]

I have a RUUD UPKA-036. The power went out last night and remained off for around 17 hours and we just got it back. The heat came on and thermostat showed the temp at 60 in the house and the heat was set at 68 and the auxiliary was on so I turned down the heat to 62 to save some money. The aux remained on so I turned it down to 61 and it still remained on. I thought the aux heat only came on if you increased the temp by 3 or more degrees at one time or if it was too cold outside for the regular compressor to work. It's about 40 outside right now. We have never lost power during the winter before for this long a time. Any explanation or help is appreciated. Thanks.

[nomadpeo]

so you know for sure that your outside unit is running and functional * feel the copper lines. the big one should be hot. if it is not working, you may want to set your stat to emergency mode and consider calling for service. update us when you can.

[cujok]

It appears to be back to normal now that the house has warmed up.

I read somewhere that if the power goes out for several hours you should allow the heat pump unit to rest for several hours with electricity going to it in order to heat up the compressor oil prior to turning it back on. Evidently the compressor has a small heater in it and if this compressor oil is not warm enough the auxiliary heat will be turning on until it warms up. Does this have any *

Thanks

[nomadpeo]

you are referring to a crank case heater. it's job is to keep the oil warm during the off cycle so that any freon that has migrated to the compressor and condensed to liquid gets boiled off. liquid refrigerant in the crankcase will displace the lubrication and the oil will float on top. on startup, a condition will exists that causes what is referred to as 'slugging'. the refrigerant will literally explode out from under the oil and can cause damage. if there is a timer to keep the unit from running for a while after power is restored for that reason, it would be there by design of the manufacturer. it is not common in most units.

[cujok]

Thanks for the explanation Nomad. The system is working as it was prior to the loss of power.