Hi,

Specs: 1994-ish Marquis spa (ME-42-0-xxxxx..)
240V on new 50A GFCI breaker
Two 2 hp jet pumps, 1 recirculation pump, 4.3k 240v heater.
No Ozone, No Blower.

I got the tub used from a dealer who took it as a trade-in. He reported it was 104 degrees and running perfectly when he drained it, and the only problem was a nuisance leak in a fitting and it had no cover. It has been several months and I finally got around to fixing the leak and wiring the tub, and now I'm having some electrical problems.

The 50A GFI breaker popped off immediately upon power up. If I unplug the recirculating pump, the circuit no longer trips. I replaced the pump (and mistakenly replaced the heater before that) and I get exactly the same result. Just for fun, I wired the new pump to a 120V GFI receptacle and it runs perfectly and does not trip the GFI. This leads me to believe that there is a short to ground somewhere in the circuit board.

Question 1: Does anyone have experience to suspect some other cause of the problem?

Question 2: Assuming it's a bad board, I'd rather not spend another several hundred dollars to replace it (and not sure I can find the right one anyway), so I was thinking I could bypass the problem by powering the recirculating pump directly off one leg of the incoming power (bypass the circuit board altogether). I think it's okay to do this because the recirculating pump should run 24/7 for filtration; and I'll install an inline fuse to protect the motor/wiring. Think it will work? Think it will break anything if I try it and it doesn't work? Any other suggestions?

I appreciate any help you can provide.

It's possible the gfci breaker is wired improperly... If everything else is 220v, and the only 110v component is the circ pump.

Be sure the neutral wire that runs between the GFCI breaker and the spa is wired to the proper terminal on the breaker, and not the neutral bar.

I'd look for wiring/install issues first.

Hey Swine (feel like I'm being mean calling you that), thanks for the help! I only wish I had asked $400 ago (before I needlessly replaced my heater and circulation pump). I used to sell hot tubs and electrical building materials, but I never wired one myself with an external GFI breaker (last one had integral GFI on tub). Given a little bit of thought it makes perfect sense why the neutral goes through the breaker instead of directly to the neutral bar... otherwise any 110v device would trip the GFI because current flowing through the neutral would be considered leaked/lost to the breaker. DOH!

Anybody want to buy a used (but in working order) 4.3K heater and recirculating pump for a Marquis spa?

You should hang on to those parts.

In a year or so you'd be kicking yourself for getting rid of them.

I hope I don't need the vintage 1994 equipment as a backup to the brand new stuff I just put in, but you're probably right. What's two more pieces of junk among hundreds of other unnecessary items taking up space in my garage?

Obviously Murphy ain't started using your tub yet. And no I'd never get rid of something that was actually working - that expensive, and would fit my tub.

You'd be surprised what can happen within a year or two.