Posted: Sun Nov 05, 2006 8:53 pm   Post subject: Heating Woes

Hey, everybody. I'm having an issue with my hot tub, and I was wondering if you could lend me some insight. I own a Great Lakes Spa. Not sure what the model number is, but it's a four seater that can be hooked up as 110 or 220. Up to this point, we've never had any troubles with it. Guess that's why you've never heard from me until now.

We recently moved into a new house, and decided to convert the tub over to 220 from 110. There has never been any trouble with this hot tub while running on 110. It's just that the new place had a hot tub pit that was set up for 220. After getting the electrician over to do the conversion, we filled up the tub and fired up the power. It ran for a bit, but then it tripped the GFCI switch in the breaker box. Every time we'd reset the switch, it would just trip it again. About ten seconds before it would trip the GFCI switch, the switch inside the power box that controls the heater element (I think it's called the pressure / flow switch) would also click. We called the people who sold us the tub, and they told me to disconnect the element itself and try to run the tub that way. They said that if the GFCI didn't trip, it meant that the heating element was bad.

I did what they said, and sure enough, the tub stayed running. So, we went and bought the element, installed it, and put everything back together. FYI: even though I replaced the element myself, I'm POSITIVE that I hooked everything back up correctly. After we got everything done, we fired it up, and the GFCI didn't trip. I thought all was right in the world, and waited until the next day so that I could get in.

Well, I come back in the morning, and the temperature had actually dropped (we'd filled it with hot water). Upon further inspection, I discovered that the same switch (the one that I think is the pressure / flow switch) is still tripping within 30 seconds of powering up the tub. So, it's cutting power to the heating element, even though the tub stays running. I'm sure that the flow is not an issue. I cracked every joint in the plumbing, and water is coming out of each and every one of them. The pump is running fine and all of the jets are blasting like gang busters.

So, does anybody have any idea what is tripping that switch? Thermostat, maybe? Maybe the switch itself is bad? Are there electrical components that need to be changed when converting over? Though I'm no electrician, I can read a flow chart. I looked at the one on my tub and checked the electricians work. Everything looks correct to me. Any help you can give would be greatly appreciated.

Thanks Jon

Yes sounds like it may be the pressure switch but I would not rule out that you need to flip a switch on the pc board to complete the 220v conversion. You can contact Great Lakes directly and ask for tech support at 1-800-458-1476. Ask them what dip switch needs to be changed for a 100v to 220v conversion. If that is not the issue then replace the Pressure Switch. There should be a number on the switch itself. Make sure you kill the power to the spa, close the slide valves, then loosed the heater union (nut) before unthreading the Pressure Switch. This will keep the water off of your pc board and causing more issues.

Okay, time for a bit of an update. I haven't figured much out yet, but I'll tell you what I do know. I told you that the heating element was replaced and, while that stopped the GFCI from tripping, the relay on the circuit board is still popping open which breaks the circuit and won't allow the heating element to run. Well, after reading a fair amount and getting suggestions from a few people on these forum sites, I decided to see if the pressure switch was bad. I was sure that I didn't have an air lock situation, but it would've been logical to assume that a bad pressure switch would think that I had no water flow, which would cause the relay to trip. So, I went and got another pressure switch and installed it. That didn't change a damned thing. The situation was identical to what was going on before.

I called Great Lakes to see what they had to say. I told them that I'd changed the element and tried a different pressure switch. I also told them that I'd heard about the high-limit switch, but couldn't locate it. Apparently, when your tub overheats, it will trip the high-limit switch, and, on many of them, you must manually reset the switch. Well, they told me that the high-limit switch on my tub is not one that requires you to manually reset it. Oh, and I still don't know where in the hell that switch is.

There was a suggestion about the possibility that I over-tightened the heating element, which can crack it and cause a ground fault. If I'm not mistaken, wasn't it a ground fault that I had that was tripping the GFCI switch? The GFCI is no longer tripping. The only thing that's happening is that about 20 seconds after powering up the tub, the relay on the circuit board that controls the heating element is popping open and breaking the circuit. It tries to run the heater, but eventually gives up and shuts it down. If I'd messed up the heating element and was getting a ground fault, wouldn't it still trip the GFCI and not just the relay on the circuit board?

Oh, one more thing: my tub is a Manitou by Great Lakes Spas. It was purchased in 2000, and apparently was the last of its kind, meaning that it was made to run on 110 or 220 with only minimal conversion. By that, I mean that neither the heater nor the pump needed to be changed for the conversion to work. The next time Great Lakes made that tub, it was 220 only. I don't know all of this stuff as gospel. I just know that this was the information I got from the dealer when I bought it. I guess that they could be wrong about that.

Here are a few more facts that might help. The tub ran for years on 110 power with no problems. It gets stored every summer. We empty it out and put it away. The last time it was emptied, it overheated. It had not been run at all since the OH error code showed up. When we powered it up, it showed no error code. The temperature read-out was correct and the LED was on, showing that the spa side control was calling for heat. The pump is working fine and all the jets are kicking ass. Just got no heat!!

Thanks for all of your help. Jon

P.S. Oh, one more question: somebody said that there are separate pumps that run the jets and the water flow through the heater. Something about a circulation pump? Can anyone elaborate on that? I don't think this is the issue, though. I'm pretty sure that the water is passing by the non-working heating element and out the big hole to the right of the captain's chair.

All right... problem solved!!! Turns out, it wasn't an issue with the tub at all. There is a GFCI breaker inside the house one the main breaker panel. Then, outside of the house, attached to the deck, there is another switch that's not a breaker, but can be used to cut the power to the tub. Turns out that switch had 240V going in, but didn't have that much coming out. So, the tub was getting less than 240V and the heating element wouldn't fire up. We replaced the switch and we're back in business.

Thanks for all of your help, guys. Jon