I have a Sundance sentry 724 hot tub, yes I know it's a little outdated but I cant afford to buy a new one. Anyway, the heater on this baby stopped working for me a little while ago and I have been pulling out my hair trying to get it up and running again. I replaced the heater and the pressure switch; the pump, display, and temp sensors are working correctly. it was heating off and on kind of getting close and then not raising temperature for quite a while even with the new heater, I then replaced the pressure switch and instead of fixing the problem it made it stop heating all together. So, before I go any further into this pit of despair I thought it best to ask for some help, if anyone has any suggestions I would love to hear them. anything helps.