Crankcase Heaters

Old 06-29-10, 01:40 PM
Thread Starter
Join Date: Apr 2003
Location: Ohio
Posts: 2,404
Received 43 Upvotes on 39 Posts
Crankcase Heaters

A short in a "crankcase heater" caused a compressor shut down which my HVAC guy removed for repair. I am having trouble with the concept of the need of a crankcase heater, when the AC compressor isn't used in the winter time here in Ohio anyway. Can someone explain this to me? If the crankcase heater is needed in the winter time anyway, is this a big energy user too?
Old 06-29-10, 02:37 PM
Join Date: Sep 2009
Location: U.S. Midwest
Posts: 1,173
Upvotes: 0
Received 0 Upvotes on 0 Posts
The crankcase heater keeps liquid refrigerant from pooling in the crankcase and diluting the oil. If your A/C unit has a crankcase heater, you can de-energize it during the winter by simply tripping the circuit breaker for the condenser unit. BUT - you need to close that breaker again at least eight hours before operating the unit the following spring/summer. If you might not remember, then best to leave it on all year. (Or maybe you remember late, and have to swelter for eight hours until you can turn on the A/C.)

I think most crankcase heaters consume less that 100W - let's say 50W for discussion purposes. If you turn off the heater for, say, 5,000 hours per year, that saves 250 kWh. At 10 cents per kWh, that is $25/yr.

Now, if you forget to energize the heater in the spring, and damage the compressor, that could mean up to $1,000.

Last edited by Mike Speed 30; 06-29-10 at 03:55 PM.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: