My husband and I got a 1999 Hot Springs Jetsetter from a friend last year. It worked fine all last summer and we maintained it through the winter as well. However, about a month ago the water in the tub stopped heating. I don't think it's a heat loss issue because we have a very good cover on it, and you used to be able to put your hand over the water return and feel a noticeable temperature difference and now it's just circulating the water.
The previous owner told us he'd had problems with the relay to the heating element and gave us a spare set of relays, which we replaced but that didn't help at all.
I've been looking online for a wiring diagram or some sort of schematic so that we know what's what in the equipment panel. We aren't sure where to begin and can't afford to call out a repair tech. My husband's the electronics wizard by trade so he's pretty sure he can fix it, but this is our first hot tub so we aren't sure where to begin.

It depends on what type of heater it has. 2 types have reset buttons on them and 1 doesn't. If it has a NoFault6000 heater it has a reset button on top. If it has a NoFault Tribend it has a reset button on the side of the black base. The new NoFault titanium heaters do not have a reset button.

If it is not the reset button, then you would need to check the relay that the heater wires are attached to for proper voltage. 110volts or 220 volts depending on how you are set up.

If there is voltage then you can check the heater for continuity. You should get a reading of 9-10 ohms or more. If the heater reads "open" when testing then it is bad.

Hi Dan, I'm looking for some help from you here. We have a Jetsetter bought in either late 2001 or early 2002, can't remember exactly. In 2005 the heater failed and was replaced under warranty, I've no idea what type it was. Anyway, now the heater seems to have packed up again. Having looked inside the inspection cover on the side of the tub, the heater seems to be a Tribend type as it looks like a bugle, however I can't see a reset button on it anywhere. It's positioned so that the black box part is to the left and the bugle part to the right and I've fumbled around the black box part (although I can't see round the back) and there doesn't seem to be a reset button anywhere. Am I missing something obvious or is there no button to find?

Thanks in advance

If the bugle faces right then yes, the reset button is in the back on the black base. If you look on the top of the black base (under the two hoses), there is usually a small arrow that points to where it is (although some of the early ones didn't have the arrow). The button is within a small circle about the size of a your fingertip. You may need to use a small screwdriver or pen to hit the reset button, because it is under some black rubber within that circle.