insulating the pipes

[Deleted User]

So we bought a really old house a couple of years ago and have been updating and fixing things a bit at a time. It's a two family with a one pipe steam system. The boilers were replaced around 2007. When we moved in, the steam heat was crazy. All of the radiators would clank and many of them did not have steam vents that functioned. The pressure on the boilers was also set way above 2 psi. We've got them both set to .5 cut-in now.

We've also got all the radiators tilted the right way and all of those vents have been replaced with shiny new adjustable ones. It been like night and day. MOST of the radiators don't clank , but there are still a couple that make HUGE clanking sounds when the steam starts to rise into them.

We think the 2 that still clank have pretty flat return lines running from the boiler and that may be why we still have issues. Also, NONE of the pipes in the basement are sealed. Our plumber friend loves working on our house because he hasn't had to deal with the insulation. Nice....

Anyway, we're at the point where we are going to start insulating. I'm hoping the insulation will help the last couple of problems we do have. Has anyone had success solving some of their clanks this way?

We're going to start the insulation install tomorrow. We've got 2 sizes of the preformed fiberglass tube installation as well as some of the wrap for around the joints. I'm wondering if its best to start at the boiler and work your way out or to start from the outside walls and work toward the boiler. Or start at the areas where we think the problems are. We're probably going to do the project over a couple of weekends.
Thoughts?

Fred

If those two supply lines don't have any pitch to them, insulating them won't fix the banging. They need to be pitched to let the water run back to the Main. If you have enough clearance to raise those two radiators up, maybe a half to 3/4 of an inch, using a shim under each leg, and then re-pitch the radiators, that may give you enough pitch on the pipes to solve the problem.

[Deleted User]

I was thinking that. There is definitely room on one of them to lift the radiator onto a 0.5 inch board. We'll try that. The other radiator is much larger so haven't tried to lift it yet. We'll try the one first to see if that helps.

Jamie Hall

Do check the pitch on those two lines -- for the full length of the lines (you are looking for sags) -- before you insulate them. Much easier...

Doesn't really matter where you start. Just have at it!

New England SteamWorks

Agree, insulation unlikely to help. But, it could! With the insulation you'll have less condensate in the pipe(s), and it's the condensate that is banging.

Hope you are using at least 1" insulation.

Doesn't matter where you start. Personally, I always like to start where it's the most difficult and access is the hardest.

Leaving the easier stuff as one gets closer to happy hour...

BobC

When lifting a radiator I use a couple of 2x4's, a stubby one as a fulcrum and a 3-4 ft one as a lever. That allows me to lift them nice and slow and it saves the back.

I cut strips of plywood (1/4, 1/2, 3.4") out of oak plywood so I can both lift and control the slope. Those strips can be stained so the blend in with the floor better.

Bob

acwagner

Now is a good time to check all your pipe supports, and add additional if they are missing, loose, or were never there to begin with.

It sounds like your hearing water hammer, but unsupported pipes can make noises when they expand and contract from the temperature changes. I found on my system its usually on the cool down more than on the warm up. But, anyways, something to consider before you put the insulation on.