Buderus GB142 return pipe help?

Gurn

The buderus gb142 return pipe 7099965 has a groove where it connects to a compression fitting (part 75977)

Does this serve a purpose that I don’t understand? There is no O ring or seal associated with this part on the diagram?

Trying to keep this P.O.S. running!

Thanks! I am a homeowner, not a professional

Mad Dog_2

You're asking for trouble. You could easily make it much worse trying to repair it. Mad Dog

psb75

GB 142's were/are not P.O.S. from my opinion "out in the field." They are still supported by Bosch.

Mad Dog_2

Agreed. Me thinks he's just frustrated. Many GB are pushing 20 yrs old now...Served well. I installed over 50 or so..Mad Dog

Gurn

I appreciate the comments!

It was installed in 2013 and I am in the process of replacing the leaking heat exchanger with a new one, so not exactly built to last!

Ive already started, so no going back now…

I know how to turn a wrench, just haven’t seen a groove on a compression fitting before.

Already prepared to replace the whole unit if I “make it worse”!

Any ideas on the groove in the pipe?

Thanks!

Gurn

seriously, not trying to start a war.

I’m sure Buderus are fine units.

just trying to make sure I’m not missing something before I install this fitting.

Since you’ve installed many of these, do you have any ideas on the groove in the return pipe mad dog?

Any help would be appreciated

Thanks again!

Jamie Hall

Without seeing the fitting which that pipe is going into, I would not care to say what the groove is for. My first guess would be an o-ring but I don't see a corresponding retaining groove. It might be a groove for a retaining clip ring, with the seal being an o-ring on the bevelled end. Seen a few of those.

Or… ?

Revenant

Might be Victaulic.

https://en.wikipedia.org/wiki/Victaulic

Gurn

the pipe goes into the brass compression nipple that I also showed a picture of. I assume it’s just for referencing depth into the compression fitting, but wanted to make sure I wasn’t missing something for lack of knowledge.

Thanks for all of the replies

GW

we have battled a lot of GB142 manifold connection leaks. We did fine for years, then suddenly, we got our knee caps handed to us——all sorts of braze joints started to leak (we had to put the unit on the floor to get enough beef on the threaded fittings). It's not an easy job for the pros, so I wish you well. Maybe you'll get lucky and it wont fuss.

Big Ed_4

Its a plastic ferrel , Before you remove , buy new parts needed for the work . . Look up and down stream for leaky connections . Jerking up the boiler can open up a can of worms . Having the part needed "on Hand"is the work .. The old copper manifold "Beware" , figure up grading to the newer iron.. The union nuts , cut them off , don't waste your time swinging a wrench. …..

Use facet grease as assembly lube…