Repair solder in boiler piping


Old 01-15-18, 01:27 PM
Thread Starter
Join Date: Oct 2005
Location: worker
Posts: 130
Received 0 Votes on 0 Posts
Repair solder in boiler piping

See the attached pics, I have a bad solder in my 1-1/4" boiler piping between a valve and a spirovent. Been a while since I sweated pipe, and I don't have much experience with larger pipe. But I do remember sometimes having trouble getting a good solder once things were messed up. This has been leaking slowly for years, but recently got worse, maybe a couple cups a day. My main goal is to not doing anything that requires me to replace the expensive Spirovent.

Couple questions. Should I remove the tubing from the spirovent, and replace it with a new piece? Or should leave that good solder to the Sprirovent alone, and work with the corroded tubing? Also, for this pipe size (1-1/4), do I need to use MAP gas to get enough heat, or is normal fuel ok?

Any other tips are appreciated. Thanks.
Attached Images   
Sponsored Links
Old 01-15-18, 01:45 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,197
Received 376 Votes on 353 Posts
Welcome to the forums.

I don't think regular gas will get that hot enough. Mapp gas would do it.
You're going to have to cut the system some where to the right of the valve to get the valve out. Try heating just the valve so that the solder is not disturbed in the vent.
Old 01-16-18, 04:48 AM
Join Date: Oct 2015
Location: Ct.,USA
Posts: 1,218
Received 33 Votes on 28 Posts
First I would try to resolder the leaking joint. If that doesn't work go to disassembly. After removing the water in the pipe.clean the leaking joint really good. Apply flux to the joint extending a 1/4 inch on each side. Attempt to solder the joint a 1/2 inch wide. Good luck.
Old 01-16-18, 05:55 AM
Join Date: Jan 2010
Location: North East Kingdom of Vermont
Posts: 2,533
Received 0 Votes on 0 Posts
I've NEVER been able to remove all the water and have always created unending pressurized steam that frustrated my efforts to re-sweat a joint like this . . . . but others have succeeded (I don't know their secret); so I guess it's worth a try.

Though it's way too late now, why do you suppose the original plumber had a problem in this area and created such a weak joint years ago. You want to avoid recreating the same issue.

All I can suggest is that you allow enough time to disassemble to components and clean and dry them out completely, so they're like new . . . . so that you only have to do it once. That'll be frustrating enough !

Good luck !
Old 01-16-18, 06:10 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,197
Received 376 Votes on 353 Posts
Yes..... the unending steam issue. That is a problem and will be more so trying to solder that fitting as it is.

If you attempt to resolder in place..... get a roll of fine grit emery or crocus cloth and clean the corrosion first or it will get drawn into the joint and it will for sure leak. You need the pipe to be shiny copper and the valve to be clean.

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
Display Modes
Ask a Question
Question Title:
Your question will be posted in: