Isaac-1

I had much the same problem with my 1998 Jetsetter when I bought it used a couple of months ago, mine turned out to be a dying circulation pump that was not providing enough flow to keep the heater from tripping on overheat. At first it would provid enough flow if set at 101 degrees, but no enough if set at 103 degrees. In my case the pump performance deteriorated rapidly and started making a clacking noise, possibly related to the fact the tub had been stored dry for some time.

thanks for the update, glad you have it going

I hate to ask the obvious, but could supply side voltage be momentarily dropping enough to cause the relay to chatter? Have you check wiring connections at the breaker,etc. I am not sure what the effects would be on the control system, but that one power transformer onboard might provide enough power to keep the display alive, but let voltage still drop low enough for the relay to chatter.

No real suggestions, but the idea that it might be better to buy a new tub than to change out the IQ-2020 board seems insane to me. Here in the U.S. a new IQ-2020 board sells for about $300, and the relay board sells for about $125, even together the would be much less than 1/10th of the cost of a new tub. Labor to install them should take less than half an hour (there is a you tube video that shows the whole process of swapping out in about 16 minutes, I am not sure if it is sped up any though).

Even hot tubs that are only 1-2 years old on the used market often sell for 50% of original cost or less., with yours I would think even in good condition you should be looking realisticly in the $2,500 - $3,000 range at the high end. To sell it at this price would likely take finding the right buyer that want a high quality tub, as there are many lesser quality tubs of the same vintage available for free, or nearly so.

Are you using Chlorine or Bromine in your tub as a sanitizer in addition to your ozonator? Ozonators are primarily oxidizers, but do little to sanitize the bulk of the water. Oops sorry did not see the Baqua comment, it has been many years since I have dealt with them, how long has it been since you changed your water?

Have you check the ribbon cable from the control box to the panel for damage?

That serial number decodes to a Hot Spring Prodigy built in the 1st quarter of 2004, I think the current heater board for this is going to be a #77119

Do you have good water flow, have you cleaned the filters lately?

Dunecritter, do you also have an Ozonator installed with the Ace saltwater system?

Smartop, thanks for the off-topic spam

If it were me I would invest in a cheap clamp meter to get a better idea on amp draw and if it is a intermittent or continous problem. For this you could get away with a cheap $10-15 clamp meter from harbor freight or similar, accuracy is not really needed, just ballpark figures. Even +/- an amp or two would be fine.

That is like asking what is the best car for under X Dollars, a lot depends on how you plan to use it and what features are important to you.

These systems do two different things, Spa Frog is a mineral systems and the ACE systems is a diamond doped electrode Saltwater Chlorine generator. The big downside to all of the mineral systems like Spa Frog is that they primarily work against algae, and do little to nothing against bacteria or viruses. The big down side to this is when using a chlorine system visible algae is a major warning sign something is going wrong in your water. By contrast the ACE system generates chlorine much the same as if you were to add chlorine manually to the water, it does this by passing an electrical current through a chlorine generating cell mounted inline in the plumbing, one of the big advantages of the ACE system over other many brands of SWCG's is the diamond doped electrodes generate mode potent chlorine radicals than standard electrodes, it also works at a lower salt concentration than most other SWCG's which makes the water less corrosive to metal plumbing fittings, etc.

Where are you located? I assume you mean breaker and not fuse, and if so 13 amp is an odd number. Here in the U.S. most smaller tubs with only 1 jet pump require either a 15 or 20 amp breaker at 120V or most / all tubs with 2 jet pumps are wired at 50 amps at 240V.