I have a Hayward H100ID nat gas pool heater, 2 years old.
In the last couple of days, it's not working as usual - we have it set to auto run 2 hours, 2xs a day. This usually results in water temp of approx 90 degrees. The last couple of day, I noticed the water temp has fallen off dramatically.
The heater was on, but blowing cold air out of the hot air exhaust. By turning off the heater and restarting it, I can get the heater to come on and go through 1 whole complete cycle (5 to 8 minutes). Then the burner shuts off as it should - air fan runs, but the burner never fires up again.
It's like the heater has gone into lock-out mode. By pulling the plug out or turning the heater off/on, I can get it to re-start and go through 1 cycle.
I have checked the following:
- Filter backwashed
All screens cleaned
water pressure good
Following tested with multi meter-
Air pressure switch is working
Temp Limiters are working
water pressure switch working
By disconnecting the power connectors anywhere in the "red wire" side of the circuit to the control module, I can simulate the reset of the lock-out and cause the heater to go through one complete cycle.