Heater will not stay lit when it starts up initially. It will cycle 7-10 times before it stays on what could be the problem.

It wouldn`t hurt to remove and clean the flame senser real good with fine steel wool, this sometime does a lot of good and won`t cost nothing

It wouldn`t hurt to remove and clean the flame senser real good with fine steel wool, this sometime does a lot of good and won`t cost nothing