Sta-rite NG IG Pool Heater fires but won't stay lit. Fires (abnormal deep sounding exhaust smells of NG), runs less than 4 minutes & heater shuts off. Blower continues to run. The cycle will continue this way until I power it down. No error code.
Previous to this, pool water not balanced so added 25lbs of alkalinity Plus & just so happens my pool pump expired. Ordered online, replaced within 48hrs. All chemical settled to bottom & ended up in cartridge Filter. Removed and cleaned filters (caked on blue semi-dissolved chemical). Reinstalled & everything works perfectly, except for the heater. What's wrong???