I bought a house 1 year ago, and it came with a HotSprings Grandee Spa, which worked great even after I refilled it back in April 2016. From the looks of it, it was manufacturd in 1999 or 2000. Anyway, I recently refilled the spa, and noticed that the heater wasn't working. TO be honest, I am not sure if the heater had been working before the refill, or if it stopped once I'd refilled it, because we hadn't used the spa in a couple of months. When I reset the heater, it clicks and clacks, I can see water moving through the inlet and outlet lines, but it kind of moves back and forth. Then, the high limit sensor trips, everything shuts off, and the power light flashes until I turn the breaker off for a minute or so, then turn it back on.
Here is what I have done so far, for troubleshooting:
1. I tried resetting the spa and heater, with the filters removed.
2. I checked the water line coming from the heater for blockages or air...when I loosened the hose, water flowed freely from both the heater end, and the spa end.
3. I checked the voltage on the heater relay board, and it was perfectly fine.
I noticed that when I hit the reset button on the heater, I hear the sound of water flowing, I see water move through the tubed going to and from the heater, there is clicking and clacking, the green "ready light" lights up, for a second, then the high limit sensor trips. What do you folks think? Is it the entire heater? THe high limit sensors? The thermostats? A blockage of buildup somewhere? I'm hoping to diagnose this without having to hire a tech. Putting this out on the forums is my last resort.