Weil McClain CGI-4 pin short cycling


Old 12-07-17, 09:35 AM
Thread Starter
Join Date: Dec 2017
Posts: 1
Received 0 Votes on 0 Posts
Weil McClain CGI-4 pin short cycling

Iím a new member here but having been using this forum for over a year to help troubleshoot my boiler. The unit will do a typical start up but only sometimes get the pilot light going in which case the burners will light. It typically runs for about 3-7 minutes. Then the gas shuts down. The igniter tries to relight but rarely gets it the second time. All the while, the circulator pump and ďexhaust fanĒ continue to run. The unit tries to relight ever 5 minutes as it should but only lights up occasionally.

I have replaced the thermocouple/igniter as well as the gas valve. Both seemed to help but have not eliminated the problem. One thing to note is that my expansion tank has started to rust through and my high pressure release valve weeps consistently. I realize this is an issue that needs to be fixed but iím not sure why that would cause the inconsistent firing.

Iíve tested the voltage going to the gas valve when it calls for ignition and itís all over the map but rarely gets to 24v. Also, when the burners go out after 3-7 min and it tries to re-light, there is no voltage going to the gas valve.

My best guess is that that there is another safety preventing ignition. But why would it try to immediately re-light when it goes out? OR it has a bad computer module.....


Last edited by Daneff; 12-07-17 at 09:37 AM. Reason: Hard to do on a phone! 🤦*♂️
Sponsored Links

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: