Central AC not even turning on....

[Rumpltzer]

Helped my friend with her AC unit. She had something that looked similar to this, and the purple fuse with the "3" on it kept blowing. It's the fuse for the low-voltage DC side. Replacing the fuse was simple enough; bought in an auto parts store for less than $1.

Her unit also had a flashing red LED that would give a hint about what was wrong. The flashing code would be fast and slow flashes, and the key to what the codes meant was printed on the inside of the panel that I took off to get to that circuit board. In the picture above, I'm guessing that it's the thing labeled "staus code LED".

In her case, there was a DC short on the low-voltage side. The low-voltage signal that goes to the compressor out in the yard was running in a wire through the attic and popped out of the stucco near the ground at the corner of the house. It then ran underground along with insulated coolant lines to the compressor in the yard.

Problem is that the gardeners who cut her grass were weed whacking along the house every week, and they've been hitting that low-voltage DC line. Two wires were exposed, and they'd touch each other and pop that fuse. I taped it all up thick, and I zip tied it behind some pipes and buried it better to keep it away from the gardener.


Anyway, that's my case study.

So, does your unit have a flashing LED when you look at the blower unit? The one I handles had a cutout so you can see the LED flashing even when the cover is still on the unit.

 

[Red Squirrel]

Yep flash codes are another thing to look for. If you want to "reboot" it and it's hard wired (all units I've seen are) then just turn the breaker off for a bit then back on. That's assuming you found the problem (such as the clogged line) and fixed it. If that is indeed what is causing it, could be the float switch is seized too. Try to locate it and confirm that it freely goes up and down.