I have been going round and round with this Hayward Heater that I bought from a friend.
It is a first generation Low NOx propane H400 - although it is about 2.5 years old, it had never been turned on.
It has had trouble firing since the day I got it installed, and a service guy told me that these first generation heaters
were very problematic.
The heater would try to light 3 times and then go into an ignition failure (IF) shut off mode. I have been having to
shut the breaker switch off and back on to reset the heater and let it go through the 3 lighting cycle again - this would
repeat up to 4 or 5 times before it would finally light.
The first solution the service guy tried was using a larger orifice only on the one located directly underneath the heating element.
That seemed to help a bit, but it still did not light consistently.
Here is what we did today and it seems to have worked - the heater lights on the first try each time now.
First you have to remove the heating element - it is located immediately above the middle burner tube.
It has a semi-triangular shaped steel guard around it - it's solid on the bottom and has many holes on the 2 sides.
Pull the heating element out of that guard.
The actual element is about 5 inches long, with the first couple of inches covered by white ceramic. The last few inches are bare metal.
Note where the ceramic ends and the metal begins.
What you need to do is drill two 1/8" holes in the solid bottom of that metal guard that goes around the heating element - make sure you drill them far enough out so that they are past the ceramic portion of the heating element.
This seems to let the upwelling gas through these 2 new holes and into the heating element, instead of having to go around the bottom and up the sides where they can flow around it.
Simple solution and so far it seems to work beautifully.
If anyone is having this problem, and my instructions are unclear, message me and I'll be glad to help!