Water hammer and leakage/spray from multiple vents after new boiler install

Euclid

We just had our boiler replaced (one pipe steam system) and kept all the existing radiators (7) and piping. On the first fire, there was severe water hammer that shook the floor and dirty water was shooting out of several radiator air vents. The system had started up fine a couple weeks prior with the old boiler (replaced due to leak requiring frequent refilling) and we have only ever had minor water hammer in the past. The hammer starts after the vents close and seems to be isolated to one run of pipe, which shakes visibly.

The water in the sight glass is tea colored. The installer added Squick before filling and firing.

The new boiler is rated to 65k BTU, the old one was ~110k. The installer had set the pressure to 3.5-5 psi; I lowered this to 0.5-1.5 which is what the previous boiler was set to. This didn't change anything.

I looked at the installation manual and the equalizer and Hartford Loop appear to be installed correctly.

Is this a problem with dirty pipes? Why did it just show up after changing the boiler? What else should I be considering?

Jamie Hall

Did the installer actually skim the boiler? Takes most of a day. Just adding Squick and hitting the road just doesn't do it. My bet would be that the new boiler just needs a good thorough skim job. Also it will need to be drained and refilled -- without the Squick, please. This may take several iteration to get it clean.

dopey27177

Jamie Hall hit the nail on the head.

The water in the boiler must be clear without other chemicals installed.

The boiler will have to drained and filled many times if there were no provisions made for skimming. Part of the the problem will be in the return piping, that water will have to be drained of all the crud that is now in it.

Squick alone will not remove all the dirt and oil that comes in the new boiler.

Jake

STEAM DOCTOR

Pics of new install would be helpful. A bad piping job could certainly cause what you are experiencing 

STEAM DOCTOR

Also possible that returns are clogged. Working on old returns may have dislodged some sludge that subsequently blocked returns. Not likely but possible 

ethicalpaul

I fear the piping. @Euclid do not pay the final payment until the system is operating to your satisfaction. We can look at the install pictures to give you some information also.

Euclid

There's a nipple and cap installed in the skimming tap but I'm not sure if it was skimmed or not (I was at work for most of the install).

There is some blue thread compound on the nipple threads. Can I just remove/reinstall the cap for skimming or do I need to reapply something to the threads?

Photo here:

ethicalpaul

I can't quite tell from this angle, can you take another picture from the adjacent side? From the same distance.

But it looks wrong. Hold off the final payment if possible.

ted_p

ethicalpaul said:

I can't quite tell from this angle, can you take another picture from the adjacent side? From the same distance.

But it looks wrong. Hold off the final payment if possible.

Agreed!

I've studied many pics of boiler installs (good , bad, and indifferent), on this site. This one may not be the worst, but I swear that it's a strong contender for the strangest!

Jamie Hall

As said above -- near boiler piping is just wrong. No header, though I think that what I'm seeing is an attempt at an equalizer...

You can remove that cap from the nipple on the skimming port to skim. However, before you do that, drain the boiler all the way down. Then slowly fill it. You are trying to lift the oils which will be coating the inside off onto the surface of the water without mixing them if possible. Then bring it up to a simmer -- no more than a simmer, please -- no boiling (again, about the last thing you want is mixing or agitation) -- and let the water run out of the skimming tap slowly. Refill as necessary, and allow the burner to run now and then to keep it warm.

mattmia2

I think we'r looking at one attempt at a black iron equalizer that is on the wrong end and too low head on and another drip in copper that is trying to be an equalizer.

Euclid

Second angle, and only picture I have of the prior install. Looks like the header is there on the new one, just short and can't really see it in my first photo. The piping between the header and the mains is convoluted but basically the same as the prior 1990 install which didn't hammer.

mattmia2

It doesn't look as bad form that angle. The manual will tell you it only using one of the risers from the boiler is ok and what size it has to be. Many boilers require both of the tappings on top to have a riser connected to the header to produce dry steam.

Euclid

yes manual states 2nd riser optional, larger models require both

mattmia2

Probably skimming. The piping is weird but probably not so far off that it is your problem.

Is the water stable in the sight glass or is it bouncing up and down a lot?

ethicalpaul

Yeah the short short header was hiding in the first picture, I thought it might be possible it was there...but it's shorter than I expected

So I think there's hope here. After the first picture I was really concerned but I feel better now and am leaning toward oils making the water get thrown into the mains.

You mentioned a skim tapping, @Euclid, but I don't see one. You don't mean that low nipple off of that tee do you?

Other wall folks: are these counter-flow mains? Is that why it has those copper drip lines?

PS: I'm happy and surprised that this boiler is smaller than the previous one. This installer maybe gets it (except for the pressure setting)

Euclid

The water level doesn't bounce around per se but it drops significantly almost to the bottom of the sight glass during operation. Not low enough to trip the shutoff though.

Euclid

vent spray getting worse

https://i.imgur.com/e3aUHRF.mp4

ethicalpaul

Ok that’s good info about the water level. Did you see my question above about your skim port?

Euclid

yeah it's on the back side and labeled as such by the manufacturer

ethicalpaul

Ok. Do you know if the contractor skimmed it? Have you been in contact with them about this performance? What was their response?

EBEBRATT-Ed

I suspect this is counter flow based on the old tees with the copper drips

Steamhead

Has anyone checked to see if the burners might be over-firing?

mattmia2

are all the emitters baseboard?

Euclid

Talked to the contractor, he didn't skim it but will do so later this week. No idea about overfiring, we didn't discuss this.

2/7 radiators are baseboard, I think they were installed in the 70's along with some fake wood paneling and shag carpet. The rest are old cast iron. The bad hammering is on the side of the house that's only cast iron.

ted_p

The second view looks a bit more normal, but still pretty odd.

I'm guessing that's a 4 section, Burnham Independence IN4I.

To give you a clearer idea of what the piping should look like, here's the piping schematic for the, similarly sized, 4 section, Crown "Bermuda Series" BSI103 (also manufactured by Burnham Industries), with a single riser.



Note that when piping with a single riser, the tapping on the far side of the boiler should have been used; that's why the header is so short.

And that's on top of some of your contractor's more novel innovations.....

STEAM DOCTOR

How is pitch on that second "header"? Meaning the horizontal pipe immediately above the actual header. Bad pitch there will leave a water pocket.

Euclid

Drained and skimmed X1 and it's not hammering at all, for now at least. No spray from vents either. Drained water was brown and foamy with oil slicks on top. Skimmed until clear.

Water in sight glass is only dropping ~1/2" during operation now, instead of ~4", but it's still brown albeit lighter.

I just recapped the nipple because I anticipate skimming again soon, but next time I recap it do I need to apply a thread compound or tape of some sort?

ted_p

Euclid said:

......

I just recapped the nipple because I anticipate skimming again soon, but next time I recap it do I need to apply a thread compound or tape of some sort?

Yes, either one, if applied correctly will work.

In addition to providing a good seal, without over tightening, an important side benefit of properly applied dope or tape is that it makes the fittings much easier to disassemble for at least the next several years. Threaded pipe fittings that are assembled dry, or with just a coat of oil, will rust tight pretty quickly.