Circuit board keeps shorting out...
I recently serviced a split system horizontal 2.5 ton unit (attic) which had a bad circuit board & fan relay. The system itself is kind of old, 8+ years and it really looks like worse than that.
Anyway, I replaced both components and it worked well for a couple of weeks then I get the call, the evaporator fan is not running again..
I get there to find the circuit board and relay had gone out again due to humidity, the circuit board looked in pretty bad shape. I have checked the evaporator and it doesn't seem air flow is an issue.
What is the best way to prevent this from happening again?
I've even thought of mounting the circuit board outside the air handler but I'm not sure. or just bypassing the circuit board?
What do you guys think?
Due to humidity or is water getting to it? You'd have to find out exactly why the board is shorting out and address that particular issue. Sounds like the board failure is a symptom of another problem. Maybe there is an intermittent short in the low voltage circuit, maybe the unit needs to be insulated, who knows...
it ran for 8 years and is now starting to eat circuit boards, something has changed. You will have to be like a detective and go over the system. Blower motor drawing too many amps, etc.
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Take some plexiglass and use it in place of the door. That way you can see what's going on in the unit under normal running conditions. I keep all couple different size peices on the truck. Comes in handy for these kind of issues and coil icing.
If the board is:
inside the air handler
exposed to the airflow
and downstream of the evaporator
then I'd say that you have a clogged evap and water is being pulled off the coil and is dousing the board. It's called carry-over.
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