The Surge Identity

TheStressMachine

Idiot homeowner here.

I've been reading about the different causes of surging in steam systems, but I wanted to see if the characteristics of my surge narrowed it down at all.

1 Pipe system. Burnham Independence Boiler about 4 years old (sorry forgot to bring the specs on the train with me)

Within a few minutes of boiler firing up, the sight glass waterline goes up and hangs out there for a little while. Once the mains close and the radiators start venting (15-20 mins from stone cold), the waterline slowly makes it's way down in a bobbling fashion. When the radiators are about 50%-75% hot (but still venting) water makes its way into 3 of 6 the radiators on the first floor at which point the venting resembles a tea kettle and the sound is in full "swoosh" mode. Once the rad vents close it gets quieter, but the waterline has made its way down to a level around 30%.

I had some of the near piping re-done to install fix the hartford loop and replace the asbestos insulation. I also skimmed the boiler, and got some the muddy water out of the low water valve thingy. My water is now a slight rust color, not perfectly clear, not too dark either.

I know you usually ask for pictures. You'll see that I only have 1 of 2 risers which my guy suggested as a possible next step to fix (we did a "wait and see" method when he fixed the hartford loop). Before I invest that money, I wanted a gut check to see if the "up then down" waterline doesn't point to anything else obvious or combinations of other things (PH tester is on the way, but I'm told my supply water in my city should be pretty close ).

Thanks!

BobC

Try skiming the boiler, any oils in the water can cause surging.

What pressure is the system operating at, anything over 2 PSI will cause problems and less is almost always better.

Bob

Abracadabra

I'm guessing more skimming. Did you properly skim?

BTW, I wouldn't insulate the pipes to the main vents like that.

Fred

What is the Pressuretrol set at? Make sure the Pigtail (looped pipe under the Pressuretrol) is not clogged.
Are the radiators pitched back towards the supply pipe?
It sounds like you may still need some additional skimming. Very slow, using the skim port above the water line, not the drain valve at the bottom of the boiler.
The main venting looks good. What kind of vents do you have on the radiators? Rads should be vented slowly.
Post some pictures of the front of the boiler with the controls.
What size pipe is the header?

Jamie Hall

Pressure. The very first thing to check when you get home. Is the pressuretrol set properly? It must not be set over .75 psi cutout and 1 differential. As @BobC said, anything over 2psi is going to cause trouble on that system.

TheStressMachine

I believe my header is 3/4 inch.

I thought I had a picture of my controls but don't. Will be back home in a few days. Pressuretrol is new and I believe it's set to 1 psi with 6oz diff. The surging happens while all the rads are still venting so does pressure even hit the pressuretrol? Sort of thought that happened in a more "vents closed" scenario but looks like I might be wrong.

My skimming was very slow off the top, but I'll do it again. Couldn't hurt.

Rad vents are vent-rite #1.

Does the up then down glass level point to anything?

BobC

Usually unstable water lines point to dirty boiler water, your recent pipe work probably introduced oils into the water. If you do another nice long skim and the water line settles down, don't be surprised if the instability returns in a day or two, that just means oils are working their way down to the boiler.

Make sure the pressure is what it should be, your pigtail might be clogged.

Bob

TheStressMachine

Thanks for the tips. Appreciate it.

New England SteamWorks

Looks like a pretty competent install, but: there needs to be at least 24" from the waterline to the header, yours looks a little low. Most of us like to do at least 24" from the top of the boiler, so maybe that's why it looks low. But if it's too low you are going to have wet steam.

Ironman

If a boiler has two tappings (like yours does), then both of them should be used. Using only one riser doubles the velocity of the steam which will cause water to be drawn up with it.

TheStressMachine

This particular problem ended up being narrow supply valves not made for steam on the 3 problematic radiators. Replacing them solved the water swooshing sound. The waterline header length is exactly 24", so I wouldn't mind having more bit it should do. My guy (not the installer, just the fixer) acknowledges the optimal state of having two risers, but I'm not ready to spend the $. The vents sound a little wet when opening during a cycle so I think I'm dealing with wet steam to a certain extent bit no major problems. Think I'll settle.

Thanks again.