Raypak 266 Ignition Failure/no pilot sensed even though it is lit

[jeld44]

I have searched (probably not hard enough) and have not found a solution to my problem. I just picked up a used Raypak 266 electronic ignition model and am having problems with no pilot sensed/main ignition failure messages. The pilot lights without issue every time, but the spark just keeps trying to light it. I have gotten it to fire up randomly, but it only runs for a few minutes before giving me the same error. I have cleaned the flame sensor to the best of my ability with a green scouring pad without much help. I believe the ground to be sound, as checked with a continuity tester.

In an effort to be thorough, I opened up the back of the control panel and checked the voltage coming from the flame sensor to see if that is the issue. I am getting a changing value that reaches as high as about 120 mV according to my multimeter. I also went to check the amperage over the same test terminal and doing so immediately supplied gas to the main burner and it fired up and ran for 15 minutes.

I am at a loss here, and any help would be greatly appreciated!

 

[jeld44]

Well...never seen anything like that. Moral of the story don’t trust someone on Craigslist...I think he will do right and give me some money back. Guess it’s off to a new control board and maybe I make an attempt at soldering in some new traces. Never thought to look behind the panel. Second moral of the story, check for pests EVERYWHERE in case some bum like me finds this post as well! Poor little baby frog!

 

[KidneyPool]

I'm having the same problem.

I have cleaned the flame sensor

I'll have to find that.

 

[av8r]

Well...never seen anything like that. Moral of the story don’t trust someone on Craigslist...I think he will do right and give me some money back. Guess it’s off to a new control board and maybe I make an attempt at soldering in some new traces. Never thought to look behind the panel. Second moral of the story, check for pests EVERYWHERE in case some bum like me finds this post as well! Poor little baby frog!

This is crazy. Same problem, pilot lights but doesn't sense flame. Never thought of looking under the control board. Took it off and "wow", same frog, same place. Thank you jeld44!