Carrier 8000TS Control Bd Fuse blows
I replaced the 3amp fuse on the control board. Started up the furnace. Heats OK, then the A/C, cools OK. This was on a Friday. Returned the following Tuesday (home is vacant & for sale). The fuse was blown. Replaced fuse again. And again, furnace/A/C started up and ran through a complete cycle.
Code 24 flashed in both cases. Says short in wiring or controller board problem (although that normally would be a code 45) No code 45 has flashed, just 24.
Seems the furnace works for a period of at least a few hours or more? before fuse blows again. Thermostat is in OFF position when fuse blows.
Any Carrier experts know what typically would cause this problem? No burnt electrical smells noted. Furnace is 8 years old. Has not been used much the past three years except in cold weather months and temp at 54 (home has been vacant). A/C hardly used the past three years.
Thanks for your input.