Heater ignition lockout
I have a Raypak r2100 ASME 400k heater. About 2 years old.
The heater ran fine a few weeks ago through several cycles after I opened the pool. It ran a couple of times for about 10 minutes, once for about two hours. But now I get ILO, or ignition lockout, when I try to fire it up.
First, my understanding of "ignition lockout" is simply that the heater is trying to fire, but it doesn't, so the ignition shuts off after a predetermined time. Correct? Incorrect?
I have a 375 gallon tank, at about 70%. The primary tank valve is fully open. I see no kinks or damage to the lines. I've tried closing the valve a bit, etc, no effect.
Tank to heater distance is about 15 feet. The secondary ON/OFF valve just prior to the heater is fully open. I've cycled that several times.
Fireman's switch has continuity. Pressure switch is fine. None of the safeties seem to be causing interference.
There is a black pipe union between the secondary ON/OFF valve and the heater's built-in ON/OFF gas valve. The heater's valve is ON, I've cycled that several times. I've cracked the union and the gas flow is significant. Propane flow or volume does not seem to be a problem.
When I first got the ILO I ran it through several ignition cycles, turning the heater power on/off. No luck. I then cracked (opened) the union to sort of purge the system and check the propane flow. The gas flow was significant and the heater immediately fired up right afterwards on the first try. I thought all was well. Then the next day I tried again and all I got was "ILO", and since then cracking the union has no effect.
With everything set and the heater turned on, there is a "call for heat". I can feel and hear a single "click" in the heater's gas valve which I assume is the valve moving to the open position.
I hear the rapid "click click" of the ignition firing. The small pilot flame near the burner assembly lights off, so some gas is getting there. The "click click" of the ignitor continues. But there is no odor of uncombusted propane, and the main burner assembly does not light off.
So it seems that propane is getting to the pilot through the small 1/4" tube and is being properly lit off. But even though the main valve "clicks" it doesn't appear that the valve is allowing propane to the main burner assembly.
Any ideas on additional troubleshooting or possible repairs? The local gas guys are about 40 minutes away and are not interested in making a house call.
Would this warrant removing the heater's gas valve, removing the burner tray assembly, checking things out, and re-assembling?
Any help would be appreciated. I can take and post photos if needed. Thanks in advance.