I have a Hotspring Grandee (about 1998). Drained/refilled spa and soaked the 5 filters overnight in cleaner.

After refilling spa through filter box, I turn the 20a breaker on to prime, then 30a breaker.

If I run pump 2 right away I can feel the water warming on the output of the heater. As long as pump 2 keeps the heat going, it seems fine.

If I run either pump 1 or clean cycle, the water on the output of the heater no longer feels warmer.
Then the high limit trips and the red light blinks.

If I just let the tub sit to heat up, the high limit trips and the red light blinks.


Would it appear to have a clog somewhere?
Or does this sound like a bigger problem?

Thanks,
Trish and Dave

What happens if you don't energize either of the jet pumps?

If the electronic high limit still trips, possibly an air bubble in the circ pump, or more likely, circ pump failure.

Thanks for you help!
If I do not run the pumps, same result. High heat trips.

Is there a way to determine if it is a bubble or a failure without replacing the circ. pump?

I did notice 2 large bubbles in the input and output of the heater hoses while the pumps were on.

Is there a trick to clearing those out?

Just pull one of the hoses off the circ pump. Water will come gushing out, along with the air bubble. Quickly place hose back onto the circ pump.

Swine - you were 100% correct as usual!

New circ pump was the solution.

Glad you got it going,

Enjoy!