I'm in dire need of suggestions. We have an HVAC unit that is about 6 years old that is mounted on a roof in Arizona.
Whenever it rains and irregardless of the temperature, the unit will either "stick" into the AC or heating mode and will not shut off at the thermostat.
The inside temp will get down to 69 degrees or up to 86 when this is happening.
We've had 8 technicians out for a total of about 20 hours. We've gone through two new thermostats and new wiring on the roof.
There are no holes on the unit housing that would allow rain to come in.
When the unit sticks into the AC or heating mode, I have to go outside and shut it off at the breaker until it dries out after a day or two.
I realize that I just said "until it dries out", so I think that implies that water is getting into something, somewhere.
But after 8 contractors and 20 hours, no one can find the cause.
The contractors who have came out have all been under home warranty. I have to guess that the home warranty is not paying these contractors much money, although the previous two had put a serious effort into trying to find the problem.
I spent a couple hours trying to research this on google this morning but I can't find anything similar.
Any ideas? Thank you.