Raypak heater partially fixed

[deejor]

Hi all. I have an older Raypak heater with electronic ignition and honeywell gas valve. I was told by the landlord that it did not work but had the gas company test and it fired right up. Worked fine for me for several months but eventually the ignition started clicking forever and pilot would not light. I was able to get the pilot lit one time but the main burner did not light.

After searching the web and this site for awhile realized that the pilot assembly is typically the issue I ordered one and replaced (also when checking things out I saw a piece of the old piloy assembly laying on top of the main gas tube, it was a small forked metal piece that extended above the pilot flame and I believe it was a heat transfer piece to draw heat to the thermopile.

Anyway after R&R of the old pilot assembly it lights right away, the ignitor stops clicking, and the main gas led comes on, but the burner is not lighting. I tried shutting power off at the breaker to reset the gas valve control (read that if the pilot does not light within 0.8 seconds the gas valve safety will trip and can only be reset from breaker) but that changed nothing after being off for a few minutes.

I dont think the pilot or thermopile voltage should be an issue if the main gas LED comes on and the ignitor stops. Not sure what the next troubleshooting step is here.

Ideas?

 

[ps0303]

Do you not hear the gas valve make a click sound after the ignitor stops clicking?

BTW, if you have a electronic spark ignition then you don't have a thermopile.

What is the model number of the heater?

 

[deejor]

Thanks for the response!

I do hear a single distinct click after the pilot stops clicking and the main gas LED comes on at the same time. The model number is 355C and its outdoors with a vent stack.

Ok so no thermopile, but some sort of thermal sensor/switch on the pilot assembly as there is a single wire coming back from it to the gas valve. I thought perhaps there was a bad connection somewhere so I disconnected everything and reconnected to make sure I had good contact.

- - - Updated - - -

Here's a couple pics for reference. Can also get one of the control panel if that would help.

 

[ps0303]

Can you check to see if the pilot is actually lighting. After the pilot lights it should then send a signal to open the main portion of the gas valve. If there is no pilot, then you can go from there.

 

[deejor]

Yes it is lighting. I can see blue flame and the glowing tines of the fork portion that is over the flame. If I have everything primed (haven't turned off the gas line and valve) then it starts up almost immediately. I'm sure it is sending a signal as it stops clicking/igniting and the main gas LED turns on. This is when, in the past, the main gas line would be open and it would light within about 5-10 seconds. Now nothing happens for minutes. I'm almost assuming that the valve is stuck shut as everything else indicates that it should be open. Or perhaps there is some safety circuit that needs to be reset.

 

[ps0303]

No safety. If there was a safety issue the system wouldn't get this far to begin with. Do you smell gas when you hear the click of the gas valve? Can you feel the valve click? Yes it is very possible that the valve solenoid is stuck.

 

[deejor]

I don't smell gas but I can definitely feel clicking. The whole valve/pipe assembly vibrates to the touch.

 

[ps0303]

It sounds like the gas valve isn't opening.

 

[deejor]

that's what I was afraid of. I'll try tapping on it a bit and see if I can shake things loose a bit. Valve on my BBQ used to do that and if I shut the gas off and tapped it a few times with an end wrench it would start working. Failing that its looking like a $170 part.

 

[ps0303]

The only way to know for sure is to use a manometer and put it on the manifold side of the gas valve. Then let the unit go thru it's process. At the time of the "click" of the gas valve, you should get the appropriate reading, 24v, when the gas comes thru the valve. Obviously if nothing registers on the manometer it could be a gas valve issue. You could also double check to make sure that the 24V is being sent to the gas valve for it to open. If not then you have a board issue.

 

[Pool Clown]

You should hear two clicks. One when the pilot valve opens and another when the main opens. Check the wire connections, especially (all) the grounds. Check for voltage at the MV and the MVPV connections (@ the valve). You should get 24~36 volts when the gas valve is supposed to open. If you don't get voltage there, start moving upstream, to the same connections at the FENWAL. If you arent getting voltage @ the FENWAL, then the FENWAL is bad.


That heater is circa 1993, It had a good run. No shame in replacing it...