I have a Janitrol heat pump three zone system with a 5 ton and 2 3.5 ton units cooling 5500 sq ft. When may a/c is running it never shuts off. I just got a $843.00 electric bill for the month of May '05.
Issue is: The thermostat is set at 78 degrees, once the temp reaches 78 degrees the units will not cycle off. Runs continously. Need Help.

Could I have a stuck contactor? I did notice there were spider webs in the wiring area on the outdoors compressor unit?

Current example: Downstairs 3.5 units reached the 78 degrees at 10:38 am as of now (10:58) still running. I can manually move up the temp to 79 and system shuts off.

I have never had a electic billover $500. until this month.

Orginally I had this problem with the units 3 threes ago. unfortunally the service guy that fixed it passed away. Several service people have looked at it and they say it is fixed then once a load is put on it, it happens again.

[Edited by rbrown3553 on 06-19-2005 at 12:56 PM]