Hayward IF code after 45 minutes of operation

[Billandjody]

Hi All, I have a unique problem and could use your assistance. I have a Hayward 400 FD low Nox heater and continue to receive an IF code after 45 minutes of use. The unit then turns on again for, say, 15 minutes then shuts off. this happens typically 3 to 4 times when it stops running completely with the IF code on. I unplug it for 15 minutes and it runs great again for not for very long. My investigations so far: 1) gas flow per my manometer is within required 1.8 and 2.0. 2) Flame sensor has been clean and or replaced. 3) New burners installed. 4) Plenty of water flow from my 1.5HP pump. Orifaces have been cleaned.

What am I missing?

 

[ajw22]

Welcome to TFP.

Small water leak in the heat exchanger that cools and eventually snuffs out the pilot flames.

 

[Billandjody]

Thanks and I hear you. Yet a leak issue should be constant, right? And my heater works perfectly for the first 45 minutes to an hour ...... then the stopping and restarting begins ..... only to stop functioning with a IF code on the panel. And if I wait 2 hours or longer it will run for another 45 minutes without problems.