Hi all, first post, I'm looking for help on an overheat problem with my Echo tub.
The first couple times the tub gave me an OH error it actually was really hot, I think about 110F or so (checked by tub and probe) Then I started getting OH errors and the tub is just happily idling at 93-95F with the pumps running (I set it to 96F when not in use). The error clears as soon as I hit the pump button. I called to have it serviced, he taped a high limit sensor to the heater and said that should work. The next day it was OH and idling at mid 80's, OH wouldn't clear by hitting the pump button. I changed back to the original high limit and it worked again with the same random OH errors (1 a week or so over the last year).

Recently when I went out to check on it, the temp was up to 100 and climbing. In an hour or so it was up to 103 (double checked with probe). The interesting thing is that the heater was not coming on, no LED and I also took the panel off to feel the heater, it was barely warm. The pump motors were reading 160F but didn't seem to be overly warm at the pump itself.

The random OH problem hasn't really bother me, I've just lived with it for a year. I'm putting my house on the market this month and would rather advertise a working hot tub. If anyone has any experience with this goofyness or can give me some advice on more troubleshooting, I'd really appreciate it. Thanks a lot!

Replace your temperature and high limit sensor.

If it doesn't work you need a new board.

Can the pumps somehow run so long that they get hot and start heating up the spa like this though?

yeah but your temp sensors are outta whack with each other.

if you set it to 96 - it should stop the heating cycle when it gets to that point, not continue on and on until it overheats.