I have a 1996 hot springs Jetsetter. I got it used a few months ago and it worked fine initially. The only problem was that the water was really warm,but never really felt hot. About 3 weeks ago it sprang a leak in the equipment compartment so I unplugged it, drained it and ordered the parts to fix it (it sat dry for about 3 weeks). It's been about 4 days since I refilled it and the water temperature hasn't risen above 82 degrees. Here's what I know: It's not the heater, as I have worked around the heater relay in the control box and gotten the heater to work (actually puts out nice warm water). I don't believe it's the flow switch (there are audible clicks from the transformer in the control box when the flow switch is unplugged/plugged in and an I put an ohm meter on the flow switch...0 ohms when the circulation pump is NOT running, pegged out when it is running). I've taken out the thermistat board and the hi limit board and inspected them...there are no burnt places or even smudges anywhere (they look brand new). At this point, I'm thinking thermistors (I checked them with the ohm meter also...the thermistat thermistor read 5 ohms and the hi limit thermistor read 8.4 ohms with the water at 82 degrees).
I'm at a loss here b/c I don't have a clue as to how I could test the hi limit board or the thermistat board to see if they're ok...any ideas? And, I don't want to buy thermistors and both boards if it's most likely just a couple of $20 thermistors...I need some feedback, please.