I am a new memeber. Hopefully I get everything correct. My pool is IG and has an accompanying spa. Pool is 35k gallon, cartridge style filter system, hayward LXi no-nox heater. Have a worrysome symptom going on with the heater. When the heater is activated, the pr-blower comes on, the gas valve opens and the unit ignites normal. Later when the unit goes into another heat cycle, I hear a bif wooosh (small expolsion). It seems like there is too much gas in the area when the heat element fires. Looking for some help.
Pump/filter/heater all replaced 4 years ago. Ignititon control replaced on heater in May this year. Pool located in Southern CA.