Raypak heater - intermittent problem with pilot lighting

[mclean]

I have a Raypak 256B pool heater (natural gas).
For the past two seasons and I had an intermittent problem with the unit firing up.
Here is the typical symptom I see (used to be 25% of the time 2 seasons ago, now it is 95% of the time) :
I turn the unit on, I see CFH on the display, I hear 2 sparks/buzzes, and then ILO appears on the display (no more sparking).
I determined that the pilot gas line orifice is not clogged.
The issue looks to be (at) the gas valve. When the problem appears (again it is not every time I try), it seems that the pilot solenoid in the gas valve is not opening (so no gas getting to the pilot assembly). I measured 24VAC across PV and C (red and yellow wires), but am no expert on what else I need to check on/near a gas valve. [note that I see 24VAC from the time I turn on the unit until the time I turn it off,ie, even see 24VAC when the unit is not sparking and ILO is displayed].
The only other thing I can add is that when the unit DOES fire up normally, it tends to be on very sunny days (I am assuming that this condition would create a higher temperature inside the heater, which maybe is changing the physical properties of some device/connection such that "normal" operation occurs..??) Also, when it DOES work, it will tend to work (fire up) successfully repeatedly if I try turning it off and on several times in one session.
Any ideas on how to troubleshoot this?

 

[gkruske]

Welcome aboard! Seems like a lot of us Raypak owner's (including myself) are having issues this season.

Do a quick search for 'raypak'. A lot of results with folks having main burner/pilot firing issues. Common solutions seem to be anything from the pilot assembly to the PC board itself.

As a side note...ILO = Ignition Lockout. Means it's tried too many times to ignite the main burner, and is now taking a short break. I had the same problem, intermittent as well. I had to replace the pilot assembly, and has been working fine since.

 

[mclean]

I appreciate your input.
Yes I have read all I can about Raypak on this site and others. But have not found anything conclusive (that matches my symptoms and provided a potential solution)
I looks like you had some challenges with your Raypak in 2009, but I did not note any final conclusion/resolution posted.

I am looking for help on troubleshooting on my problem - which is intermittent.
The fact that my unit OCCASSIONALLY fires up tells me that the pilot assembly is OK.
It seems like my pilot gas valve does not open consistently.
Can anyone help me determine if , for example, that this is a symptom of the PC board being faulty, OR, some other component/connection issue that is effecting the correct voltage from getting to the gas valve solenoid, OR, is this a symptom of my gas valve gradually failing??.
If it IS (by popular opinion) the PC board, that is not an inexpensive part, but at least it is easy for a DIY type to install.
Replacing the gas valve looks to be well beyond my scope (and by code, I suspect that a licensed contractor is probably required to do the work since I have a natural gas connection)

 

[gkruske]

My issue was nearly identical to yours. For a couple years, the heater was difficult to fire when first turned on. It somehow ironed itself out after a few cycles of trying, then no issues after that. This year, it never fired at all. Raypak tech support has been recently farmed out to local distributors, and was instructed to start with the pilot assembly itself.

It was explained to me that it basically equates to misfiring in a car. If a spark plug wire becomes cracked/brittle, or the porcelain around the spark generator becomes cracked/brittle, then it can't generate the spark needed to signal the PC board to keep the gas valve open. As deterioration progresses, the problem becomes intermittent, and then can't do its job at all.

He told me to start inexpensive.....get the pilot assembly and go from there. The PC board (I'm with you on this) is horribly expensive, and should be a last resort.

A good place to start to remove the ground wires, and wire brush the connections REALLY good, and tighten them down well. 24V is little current that needs good grounding.

Hope this is a good starting point.

 

[mclean]

I am the original "poster" (ie, the one that had the problem with my heater not firing up). Just for the record, in case others are reading this post with hopes of gaining insight into fixing a similar problem, let me say that I DID replace my control/PC board, and since then, I have not had the problem. I found the board online for less than $200 and it was very simple to install (less than 30 minutes). I wish that there had been a solution that would have cost me even less, but since I replaced the control board myself, I shelled out a WHOLE lot less than if I had called in a service technician.