Raypak 130a heater lights, immediately goes out.

[PrivatePilot]

In the vast majority of cases like you are explaining, the system board is the issue. It's not sensing the signal from the ingnitor to say that it lit and is still lit.

Thanks - is there a way to 100% confirm the systemboard issue through diagnostics, however? I've always been a big proponent of diagnostics to confirm something is broken or not working as it should before replacing it, especially when said part is going to cost me $200 or so by the time I get it to my door.

I'd hate to throw a $200 part at the heater only to discover afterwards it's doing the exact same thing.

 

[ps0303]

Fortunately I have the luxury of having the parts to be able to swap in and out to see. So the pilot lights or no? I know you bought a new ignitor so I was wondering if it was working or not.

 

[PrivatePilot]

It's DSI ignition. I described exactly what it's doing now (not originally) a few posts back.

What makes me question it being the main board is the fact that once I manually light it and let it run for a few minutes it will shut off and relight just fine - yesterday after it was running for a few hours I turned the power switch off and then back on about 10 times for diagnostic purposes...and each and every time it re-lit normally.

It's only when it's cold that it seems to short-cycle the ignitor and stops trying to light before it ever gets close enough to actually lighting.

 

[PrivatePilot]

I worked on it some more today and I think I've narrowed it down to being a poor ground between the igniter and or ECM and the chassis.

This makes sense as, based on my understanding of things, it seems to use the chasis ground as the feedback circuit for the ignitor.

As soon as I relocated the ground to a few alternate locations the unit stopped short-cycling on the ignition cycle and would actually light. Sometimes it would light and then almost immediately turn off, however at least it was lighting reliably.

I relocated the ground yet again in the unit lit and stayed lit, however by that time it had been running for perhaps a minute or so total, so I'm unable to confirm if it was the ground that solved it or the as yet unexplained "once it's been lit for a while it works better" phenomena I've experienced before.

I'm starting to wonder if that once the burner lights and the chassis heats up, it's leading to more solid grounds that results in better spark/ignition sensing, and in turn, more normal behavior.