96 Hot Springs Sovereign 230V with dedicated GFCI panel w/ 30amp and 20amp breakers. Pump and light work fine but when I turn thermostat up to call for heat the 30amp breaker trips. The 95/96 models have single tube heater plugging into bottom of control box. When I check the socket it provides 230V when thermostat calls for heat. Checking across prongs on cord I get 9.x ohms and no short to ground or body of heater(one and the same no?). Can anyone tell what is going on.

I'm prepared to get a 6kw no fault pdr heater and the retrofit kit to hook it up if necessary but has the heater really gone bad? Thanks!

So between the flat prong and one of the round ones on the heater you read open line?

From flat prong to either round it is open, 9.x ohms between the two round.

Strange...maybe the breaker is bad and once there is a little draw on it it trips?

Not many of those cartridge style heaters left though either. If the heater reads open to ground it shouldn't normally trip the breaker.

Had the flow switch shutting me down a year or two ago(turned out to be dirty filters) and the guy who helped me said mine was probably one of the few left.
Perhaps a little history of recent use: I shut the tub down and drained it for this summer for the first time since I bought it new. Before I did that I was having trouble keeping the 20amp breaker on when starting up but after a few trys it would work fine. Also moved the tub a few feet and had an electrician extend the wiring, but it all appears to be as before and everything else works but now the trouble with the 30amp breaker. Browsed a tech manual at the spa store in town this afternoon but that was way too much information overload and the fact that there are four circuit boards, et al, makes me not want to mess in the control box if I could even figure how to get in there.
So you're saying the readings are as they should be? I'm really stumped now!

Oh, if it was re-hooked up and hasn't run for a while I would double-check the wiring. The heater sounds good based on your meter reading.

But isn't 230v across the sockets for the round prongs correct also? I wish I'd labeled the wires when I disconnected them but I'm with the electrician in it being a pretty straight forward hook up? Any idea which might be crossed up?

Well, I believe my $285 was ill-spent. Could someone look at these photos and tell me where the electrician screwed up? As far as I can see the original install relied on the metal conduit for the solid bond to subpanel, then this electrician ran only a bare #12 solid bond to tub. It also looks like he ran only a #12(supposed to be # green ground to tub. He appears to have gotten the #10 red and grey(supposed to be blue) run from the 30 amp breaker to the tub okay.
I don't understand why I have 230v across the terminals of the 20amp breaker where he attached the red and orange wires(diagram says 20a 115v) or why there are even 3 wires off the 20amp? That looks totally wrong.
The first electrician must have taken off with the original instructions that came with the subpanel but this diagram in the predelivery instructions seems to show all the wiring?(up to the tub anyway)
He's got seven wires running to the tub and there should be only 6! I hope this hasn't fried something.

Is that the same panel and breakers that you had hooked up before? It is not the panel that is supposed to be used with a convertible Sovereign. The diagram shows a 30 amp double pole breaker and a 20 amp single pole breaker. Your setup has a double pole 20 amp breaker.

If it was working before with that setup then the original electrician probably knew how to make it work even though the panel was wrong. I'm not an electrician, so understand this this is just a guess, but it looks like right now you have two hot wires and a white neutral coming from the 20amp to the tub, and you need one hot wire and a neutral instead. Don't quote me on that but I think that's your problem.

This is the panel supplied with the tub. I concur with your observation Dan. This guy showed up with no notice and no one home and tells me after the fact he knew nothing about hot tubs just wiring. He apparently failed to replace the wiring as it existed! I'm not happy, wish I hadn't paid him till I had it working. Dam* it! " title="Evil or Very Mad" /> There had better not be anything damaged. Dan, do you know anyplace on the net with the step by step instructions for 230v tubs supplied with the sub-panel? There are two red and two blue and the white coming out of the control box which seems to call for the seventh wire? I plan on getting him back to do this right, he owes me a couple of lengths of #8 gauge wire at the least! " title="Mad" />

I would have to check to see if I can find any tomorrow if I have time. I thought there was a diagram of sorts on the back side of the silver box cover, no?

Right, forgot that one, and it shows he has it right there! Looks like the only problem is too small a ground and bond wires. Wonder if that would trip the gfci on the 30amp breaker or if it's just going bad? " title="Confused" /> Looks like Watkins pre-delivery instructions are misleading! edit: Our tub follows the Grandee & Highlife diagram!

Found a dealer with one of the discontinued cartridges to fit this old heater! Actually goes to a Tiger River so I'll have to splice my plug on but it'll save me a couple of hundred dollars! He also said the ground should be at least a #10. Also said he had an element on his desk that had ohmed out okay but was shot. I'll let you all know if this fixes things!