I have a two year old Hayward H250FDP heater for my spa that has recently developed a minor problem (for now anyway).
After draining and refilling the spa, the heater will light and stay lit for about 60 seconds. It then stops heating for about 30 seconds before it relights.
It goes through this cycle about a half dozen times before it stays lit until it reaches the desired temperature.
Does this sound like the flame sensor is getting ready to go kaput?
Or something else?