The condensing water sometimes backs up and shuts down the boiler. I am told this may be an airlock in the drain pipe and this can be cured by fitting a "tunney". What is a tunney and where can I get one?

Hi Alan

No idea what a tunney is, but it sounds like your condensate line may be unvented and may not have a cleanout installed on it.

Here, a simple CROSS TEE fitting and cleanout (see image) can be installed in the drain line and it can act as both a vent and a cleanout when needed. This would also allow you to periodically flush the line seasonally!

With that being said, I would check with your serviceperson and see what they were talking about because I am not there and can only speculate with the little information provided, OK?

Your thoughts?

Mark