Hi,

I have a Spa Builders AP-1 control system and the last few days it has been acting up. One, by making a loud vibrating noise (seems to be coming from the box) while running a pump, nothing touching to cause that and both pumps are fairly new and will do that for about 4 seconds before kicking off. A minute later it will repeat that same situation all over again 2 or 3 times before it stops for awhile. Then hours later it will seem fine, run quite and then all of a sudden it will start acting up again.

Now, I have worked on this pack over the last few years replacing some internal electrical parts & various plumbing components and pump motors. So I removed the cover panel and took a closer look and watched to see what would happen when I forced it to heat or run a pump. I seem to hear clicking from both contactors (one of which I replaced last summer) but nothing happens. Then I keep doing it and all of a sudden it will kick on, make that humming vibrating noise, pump shaft spinning for about 3 or 4 seconds and then stop, Then nothing for awhile with toggling the switch on, off just clicking sounds. Do it again and I hear a faint humming sound, turn it off, wait, turn it back on and get the same kick on, shut off sequence I have been getting but this time I noticed a spark at one of the screw terminals on the right contactor but the spark didn’t reappear when I tried to see if it would happen again.

So, I’m not sure what to make of this. Is it a short somewhere in the electrical system, a bad relay, a faulty connection or contactor, what? It doesn’t seem to be very consistent in what it does from one second to the next. Any advise & help pointing me in the right direction in solving this would be greatly appreciated. Thanks