I have a 10yr old (but clean, lightly used) Hayward H400FD heater that began acting up several months ago.
Unique from many other IF-related posts I've seen, mine always works perfectly for at least 30 minutes before cutting off, then going through 3 re-ignition attempts, then going to IF/service. Of the several times I've timed it, it was always around 35 minutes, except one time it worked perfectly for a couple hours, heating my spa to the 104 setting, going off as it should until the temperature dropped, coming back on, etc. I finally had to shut it off myself (I had to leave).
When the heater shuts off: the sound of the flame dies away slowly over several seconds; then another 20 seconds or so pass, then a cluck and the Heat light goes off; finally, it goes unsuccessfully through the re-ignition cycle (3 times) before going to IF/service.
If immediately after a failure I reset the IF/service state by cycling the circuit breaker and try to fire up the heater, the ignition sequence fails. But if I wait 30 minutes of so, it succeeds.
I removed and checked the orifices, and to my dismay they were all perfectly clean. I have replaced the digital display (and board) as well as the main board, but these did not change anything. I have removed and inspected the Flame Sensor and Ignitor, and they look OK.
Do you have a recommendation for what I should try next? Perhaps a new Ignitor (FDXLIGN1930), and then a new new Flame Sensor (IDXLFLS1930)? What is most likely failing when it gets too hot?
Unique from many other IF-related posts I've seen, mine always works perfectly for at least 30 minutes before cutting off, then going through 3 re-ignition attempts, then going to IF/service. Of the several times I've timed it, it was always around 35 minutes, except one time it worked perfectly for a couple hours, heating my spa to the 104 setting, going off as it should until the temperature dropped, coming back on, etc. I finally had to shut it off myself (I had to leave).
When the heater shuts off: the sound of the flame dies away slowly over several seconds; then another 20 seconds or so pass, then a cluck and the Heat light goes off; finally, it goes unsuccessfully through the re-ignition cycle (3 times) before going to IF/service.
If immediately after a failure I reset the IF/service state by cycling the circuit breaker and try to fire up the heater, the ignition sequence fails. But if I wait 30 minutes of so, it succeeds.
I removed and checked the orifices, and to my dismay they were all perfectly clean. I have replaced the digital display (and board) as well as the main board, but these did not change anything. I have removed and inspected the Flame Sensor and Ignitor, and they look OK.
Do you have a recommendation for what I should try next? Perhaps a new Ignitor (FDXLIGN1930), and then a new new Flame Sensor (IDXLFLS1930)? What is most likely failing when it gets too hot?
