Re-pipe the near boiler piping

jailibis

One of my boilers (two family house) is occasionally being noisy with sounds like water hammer and knocking inside the riser and boiler that wake me up at night. A contractor wants to repipe the near boiler piping, including increasing the size of the return and moving the main vents back. As someone outside of the industry but who lurks these forums frequently I'd appreciate your advice before I ok the job. I attached some pictures for you to critique






.

JUGHNE

Get the install manual for your model of boiler.
It will tell you if you should use 2 boiler risers and the size of them and the horizontal header. Is the boiler riser reduced at the outlet? There would be minimum height of the horizontal header above the water line.

If repiping NBP I would go for a drop header......needs 2 extra 90's and nipple. Twice if using 2 boiler risers.

Each steam main should connect to the header before the drop for the equalizer. (Is the high point of each at the boiler and slope down hill away from the boiler?)

Could there be a water pocket in the short horizontal pipe for the smaller main?

The returns might be big enough but should not tie together above the water line. Usually drop each down almost to the floor. IMO the vents are not in a bad place. But could be bigger depending upon the length of the mains. For the vents I would go up with nipple, 90, long horizontal nipple, 90 up to vents. This may prevent water hammer and debris from hitting the vents. (in effect it gets them away from the drop 90 elbow.)

Check the height of the Hartford Loop connection by the book.

Also add a 0-3or 5 PSI gauge and set pressure as low as possible.

EBEBRATT-Ed

What @JUGHNE said above

Steamhead

Looks like that's a Williamson boiler. What model?

jailibis

"Is the high point of each at the boiler and slope down hill away from the boiler?" - Yes

"Could there be a water pocket in the short horizontal pipe for the smaller main?" - Very possible, seems pretty horizontal to me, that main services 3 rads.

"But could be bigger depending upon the length of the mains." 1 Main is about 50 feet the other about 25

Thank you, very helpful.

KC_Jones

The riser and header are definitely too small according to the manual. Only the smallest version of that boiler allows for 2" pipe and I can tell by eye you don't have the smallest one. So it should have 2 1/2" at a minimum, remember that is the lowest acceptable standard.

I would do at least 3" if it was mine and many on here would use both risers.

Ideally the mains should come down to the header individually and the returns shouldn't be tied together above the water line.

Fred

Have him use both riser tappings out of that boiler as well. It sounds like this contractor is knowledgeable enough to know it's not piped correctly. The next question is does he know enough to make the correct re-pipe?

EBEBRATT-Ed

@jailibis , show him the boiler install manual. all he has to do is be able to read it

jailibis

Thanks @EBEBRATT-Ed I found it online in about 5 seconds of searching. BTW you HVAC guys must make a killing in estimates alone. Everyone wants to charge me >$100 just to come out and tell me how much my eventual bill might be.

L Thiesen

Interesting jailbis, you come on this site asking for help and then take a shot at the people trying to help you. If you think its so easy start your own business and then get back to us and let us know how its working out for you.

jailibis

No shots fired. I just never experienced that business model before. Believe me, I get it. I typically get 3-4 quotes before hiring someone to do a job and I usually feel bad that the guys who missed out on the job wasted their time. But I need to be sure I'm hiring the right guy at the right price.