I have a spa I inherited built in 1995. Vita Spa 200 I think. At any rate, I've had to replace pvc fittings (cracked in a freeze), pump 1, Motor 1, heating element, cover, etc.

Ever since we've had it, it has never kept heat. If you leave the controls at 100, the next evening the water temp is 85, or 87 or 91. It's never consistent. I have the original paperwork, so I know I am setting it up correctly.

Intermittently, the spa will trip the circuit breakers. Since it's 220v on a 60amp, it appears to be sized correctly.

Last night, I went out to turn up the heat and the power had gone off again. Unfortunately, pump 1 had ice in it and wouldn't come on. Once I got the heat gun on it and freed it up, pump one would run, but only for about 1 second at a time, then go off for a minute, then back on for 1 second, then off. It's getting power. I pulled the pack cover and the relay is engaged the whole time, telling me it's yet another problem with the motor.

Ill take one last stab at fixing this if anyone can give me some pointers, but before throwing more money at this spa, I'm thinking long and hard about it. It just seems like there's so many little things that keep going wrong that 'god may be trying to tell me something'....

sorry i dont have an answer, i was just nodding loudly in agreement, as I find myself once again up to my elbows in cold water with my Vita spa having replaced the same things you have...
It was the WORST thing that could have come with this house! it would have been cheaper and less headache to just have spent the money on a new roof.
Good Luck.

This was happening with the spa i've got - everything would run but eventually the pump would turn off and be cold when it was to be used. Turned out that it was the high pressure switch that was triggering the unit to turn off. It was indicative that the high pressure switch was dying. I replaced it and the spa seems to maintain it's heat now. I don't know if this will help at all, but it might. The way i was told to test this was to disconnect the leads running to the heater and see if the spa continues to run when these leads are disconnected from the magnetic switch within the electrical housing.