cold spa, hot springs grandee 96'

[grandee ny]

Ok, so my spa is not heating up at all. The circulation pump is shot,so while im waiting for the new pump to come in i want to check to make sure the heater didnt take a hit also. Even though the ready light on the front control panel was never blinking, so im thinking the pump must have been still pushing a little bit of water. My question is, i hooked another circ pump up after i pulled the bad one out,just to check if the heater will heat. Its a outside pond pump,so its plugged into a gfi 110 wall outlet,not the control panel. Still not heating, so does the control panel know when the pump is disconnected and wont let the heater kick on or is the heater strictly going on and off based on water flow moving through it. when the "other" circ pump is running i can hear the relay kicking on an off,but no blinking lights and there seems to be plenty of flow moving out of the bottom drain at the bottom of the tub. Any ideas would be hugely appreciated.

[Chas]

When the circ pump goes, it will overheat the heater. That usually just trips the electronic High Limit, which is reset by simply turning off the power, waiting a few seconds, and then turning back on. However, if the heater was really warm - perhaps from heating a freshly-changed load of water, or just because it had been heating for some time - then it may trip the mechanical High Limit (safety switch) located on the heater itself.

Try to find and push the reset button on your heater, and you should be fine. It will only reset if the heater is below 90 degrees.

[grandee ny]

So the high limit switch wasnt tripped from the heater and this heater apparently has no reset button on it. When i removed the bad circ pump and just put a temporary pump in its place that had approx the same amount of water flow as the bad factory pump,i can hear the heater relay kicking on and off while the pump is running. Is it because there is nothing plugged into the control box where the circ pump would normally be hooked up(i unplugged the bad pump and have this other pump just plugged into a 110 v gfi wall outlet). The tub is at 72 deg right now, but when i turn off the pump and just leave the tub on..then you dial up the heat control...and hear the relay initially kick on but then it stays on,no on and off sounds. i dont dare leave it on too long with no water flow for fear of burning my heater up. Guess i was just wondering if with nothing plugged into the socket for the circ pump on the control box,if this will automaticly keep the heater off. thanks