I started up my 1993 Advanced Spas hot tub for the first time this spring and I can only get the temp as high as 80 degrees.
When I first added water I was able to get the temp to 103 but noticed a small leak coming from under the tub and within 12 hours it drained enough water so I had to add more. Since then, the temp will only go to 80 degrees and no higher within a 24 hour period.

I noticed a couple of things:
*When I turn on the heater control I will hear a loud buzzing noise. If I turn it off and on a couple of times it will quit for a time.

*The stainless steel heater is warm and water flow is good.

*When I turn the jets on for an hour, the temp went up to 82 degrees. (Suggestion I found on this forum)

I am not sure why I can’t get the temp any higher and have looked over the forum for other answers. Please help.

Is 80 degrees the real spa temperature or the numbers on your control panel?
There maybe two problems with your spa: heater burnt-out or computer control system run-out.
Why not check it with your spa supplier? they may probably give you suggestions.