I have replace the manifold, it was really plugged up. I replace the igniter and the plate that the igniter and blower go on, Symptom was always igniter would light, blower is on and after about 10-25 seconds I hear a valve close and heater goes into service mode. I have held the pool on button for several seconds and it does say the actual temp of the water. When the heater ignites that temp goes up to 150 plus and shuts off. Would this be just a sensor? and if so what sensor?
Thank you, I have seen other similar issues here but really no answer..