well guys, this is really the first problem ive had out of this 2003 calspa. its a very basic model with only pump on/off controls, and a temp control. I hate to just start throwing parts at a problem hoping to fix it, that gets expensive. after searching through SEVERAL heater topics, it seems I have an uncommon issue:
the spa will work perfectly when heating up to set temp, at which point the pump shuts off, and the heater starts to boil the water inside it. this eventually activates the OH error code, effectively shutting down the heater and the boiling stops. I have drained the tub and refilled it, hoping I had some sort of vapor lock issue. the same problem resurfaces regardless of filter presence. the power from the jets seems strong as ever. I can reset the OH after about 30 minutes and the spa will work until the pump shuts off, or, if it is already at operating temp or set below operating temp, the heater comes on without the pump, boils the water, and shuts down again with OH error code.
suggestions welcome, TIA
puttalong