h400fdn

Looking for help! I have an H400FDN that is a 4 years old and has always worked perfectly. The other day we turned it on as normal to enjoy a spring pool day. The heater turned on, lit the natural gas as normal. An hour or so later, we noticed the heater was running, but wasn’t heating the...

Hey everyone- I am at a loss with my situation and looking for some help. I bought a brand new Hayward H400FDN natural gas heater about a month ago. Installed it and it fired up just beautifully. Ran for probably 5 hours and went out. Could not get it to light again the rest of the day. It...