Water hammer, no heat, puking rad on one line

steaminvt

Steam nube armed w/ D.H.'s books... 1856 home, newer steam boiler (2010) heats great except for 3 rads at end of house. Water hammer in this line, takes forever to eventually get these rads to heat... rest of the house gets way hot by then. What I've done: Discovered zero main vents, added Gorton #1 toward end of troubled line where I found a plug. There are 2 other plugs, one near the end of another line where it turns upward through the floor and one in the piping near the boiler. Replaced 10 of 11 rad vents with Gortons sized to slow flow near the t-stat and to speed flow on troubled rads. Added insulation to some bare fittings in the basement, adjusted the pitch and straightened the (sagging?) troubled line as best I could. Removed & cleaned pigtail, drained some water at bottom of Hartford loop. Just had boiler cleaned & serviced. Pressuretrol set @ about 1/2 psi and diff looks to be set @ 1psi.
Had Gorton 6 on likely the most troubled rad and it puked about a quart of water on its way to heating up. Replaced with a good (I think) Doyle vent, adjusted to 10, to stop the puking. I pitched this rad (was dead level) by raising about 1/2 inch on far end but didn't help.
We cannot leave system on overnight cause it wakes everyone up.

TY in advance for any guidance. (I do have some nice steam porn from this house that I'd love to share along with pics of system but how do I add pics???)

Jamie Hall

If it's hammering there is water trapped -- or at least not able to leave properly -- somewhere in that line. Since you have Dan's books, double check the overall pitch of that line, and double check that there are not sags.

Is that line served by a drip to a wet return? If so, check that that isn't plugged.

Steamhead

@Erin Holohan Haskell , can we move this to the Steam section?

Fred

Is that Radiator on the second floor? If so, there may be a horizontal pipe under the floor that has lost its pitch. Try to raise the supply end of the radiator a half inch or so and then re-pitch the radiator.

Erin Holohan Haskell

Steamhead said:

@Erin Holohan Haskell , can we move this to the Steam section?

You got it!

steaminvt

2 of 3 slow rads are 2nd floor. The one directly above the worst one is interestingly already sitting on 3/4" blocks and that floor has never been refinished. Raising anymore will be tough since the rim joists were spray foamed and the piping comes up through the floor in those areas. I chipped out most of the foam under the worst rad and tried jacking up the pipe from underneath (got maybe a 1/4") and maybe I could remove some more foam that's attached to the underside of the floor. The valve on this rad is under a lot of stress already as evidenced by some water dribbling out the bottom of the connection after I raised up the end that 1/2".
Maybe I need guidance on how much I can moved these pipes around before I crack something. There is not a lot of space available to claim in some places. I'm trying to make small incremental changes.
Still can't believe there were no main vents. All the rads had Doyles. If it makes a difference, only one of the steam risers off the boiler is being used.

nicholas bonham-carter

You definitely need plenty of main venting, and slow radiator venting, so that all the supplies fill with steam first, and the more slowly allow the radiator air to escape. This should get steam to all the rads simultaneously. A Gorton 1 is only good for 10 feet of pipe.
Are the pipes insulated? Uninsulated pipes make a lot of condensate quickly, which must be allowed to drain back.If the pipes are naked, naked, you can put a magnetic level on the pipes every 10 feet or so and mark the direction of flow with an arrow on tape. You may find some arrows pointing towards each other.
Verify your pressure with a low pressure gauge, graduated in ounces. You can also see the back-pressure of venting with the gauge, which should be less than 2 ounces—NBC

ethicalpaul

After you added the Gorton #1 to the most problematic main, did you monitor that vent during the start of a heat cycle to see if it was, in fact, venting?

You have a lot of info in this thread already. I would try to narrow things down or you will get inundated with so many suggestions.

First focus on all your main venting. Make sure that during the start of a heat cycle, you can follow the steam through each main all the way to the vent (using careful touch--you'll know when the steam gets there).

This will ensure your mains are all operational. You might also get a chance to hear exactly where the hammer is occurring during these observations.

steaminvt

Pipes are fiberglass insulated. Hard to accurately gauge pitch with them covered-- is it worth unwrapping the long run of this leg to check? Could also make a tee or 'antler' to add more #1 vents where I put the first. There is very little space to go upward where I put this vent. This vent does (eventually) breathe when I start the boiler. The heat travels remarkably slowly up this line.

steaminvt

Water hammer occurring in this line (that serves the 3 slow rads) near the boiler (pipe comes off boiler {wyed off the pipe that serves most of the other rads in middle/back of house} makes a 90 to travel 4' behind the boiler, 90's again to the left for 6-8' before it 90's to the right for the long 30ish' run) Hammer starts in the 2 nd & 3rd 90 elbow area.

ethicalpaul

Don't worry about the 90s. Worry about the vertical dimension. Look for places where water can collect.

OK for the insulation, that's fine. Don't tear it off. The Gorton #1might be making the steam favor the other mains, so they fill up before this one. But then once they are full, this one should fill up before ANY radiator in your system does.

To test it more, you can just remove the Gorton #1 and watch the hole during start of call for heat. If an open 3/4" hole doesn't let that main get steam first, then nothing will (vent wise)--in that case there must be something else going on, like a lot of water in that main in a sag somewhere that is "eating" the steam.

steaminvt

Good idea on trying with vent removed! If it helps, on the maybe the 4th of 5th boiler firing (we moved in at end of August) the boiler shut off. I investigated and found site glass full. I drained 6-8 gallons of very dirty (brown) water before water level normalized. Its like a whole bunch of pent-up condensate ' let go' and ran back to the boiler? Hasn't happened again. I will post results of start up sans main vent after I get home tonight. TY

ethicalpaul

hmm that's not great. Typically such an occurrence is related to a lot of water getting thrown up into the main, causing a low water cutoff with automatic refill. Then when the condensate returns, the boiler is overfilled. You can watch a heat cycle to see if this is occurring: Watch the water level, and watch your auto-feeder.

Post pictures of your near-boiler piping (several photos, each far enough away that we can see floor to ceiling, from several angles) and people here can tell you if it's likely that water is getting thrown up into your mains.

Watch my video on this thread to see what can happen: https://forum.heatinghelp.com/discussion/169320/see-wet-steam-in-the-wild

Jamie Hall

steaminvt said:

Water hammer occurring in this line (that serves the 3 slow rads) near the boiler (pipe comes off boiler {wyed off the pipe that serves most of the other rads in middle/back of house} makes a 90 to travel 4' behind the boiler, 90's again to the left for 6-8' before it 90's to the right for the long 30ish' run) Hammer starts in the 2 nd & 3rd 90 elbow area.

I'd be very much inclined to take a very close look at that bit of piping -- particularly the slope of the three nearer sections (Y to 90 4 feet to 90 6 to 8 feet to 90. It's very possible that one of those sections has drooped. It really takes remarkably little droop to mess things up.

JUGHNE

Someone presented this a few years ago to check pipe slope on an insulated line:
With a 2 to 4' level as desired, get 2 sharp roofing nails, both exactly 2" long, these have big heads.
Tape thru the nails to fasten them to the bottom of each end of the level.
Several wraps of tape for a secure fit.
You can test the accuracy of your new nail point level by setting it on a level (nearly) bench. Then turn it end for end and you should get the same bubble reading, if so then your tool is correct. FWIW

steaminvt

Here are some pics. Let me know if they are inadequate. Blue tape marks the problem line. One pic is of an old (and huge) hot air system (coal fired) just for kicks.

Fred

My goodness, is every radiator individually run off of that header? Steam is going to take the path of least resistance and from the looks of it, it has 6 or 8 options. All of those run-outs from the header are also pitched down, into the header, like a counter flow system but I don't see any drips from any of those pipes into a wet return.

steaminvt

Um yeah.
Tried the "remove Gorton #1 idea" with no different results.
All other radiators were getting heat first, no steam to back of house.
Water hammer started early in pipe section in pic. Pipe was shaking for first minute then calmed down to less voilent hammer. My dilema is I cant move the pipe downward on the left side or lift up the right side because it will alter (raise) the slope of the long run this 6' section serves.
After 40 minutes the room (w/ t-stat) had raised 6 degrees and still no heat to problem rad BUT there was a lot a water sloshing noise in the pipe under the floor and quite a bit of water seeped out of the aforementioned stressed connection at this rad. Its like the water gets pushed up this run.
Anyway, looks like no easy button for this one. I'll carefully check the pitch of the long run leading to the pipe in the pic and see if there will be enough travel to raise that right corner to maintain that pitch and follw that pitch through the wall into the boiler per Jamie Hall.
Second pic likely shows were wet return occurs-- that kinked pipe is connected at the very back of the header.

ethicalpaul

OK with that vent test and the water sloshing I say you basically have a trap in that supply line. Until that slope is corrected there’s no way you’ll have balance on that line.

Fred

That pipe off of the end of the Header is the equalizer. The other pipe is a wet return. Each of those pipes, off of the header, that pitches down into the header should have a drip that drops to a wet return below the boiler water line and any of those pipes that are highest at the header and pitches downward as it leaves the header should have a drip, at the end of the pipe that drops to a wet return, elsewhere in the basement. (From what I can see, all of those pipes running off of the Header pitch down into the header).
In addition to the water hammer, I can't see any way you can balance the steam flow with the current pipe configuration. Steam will take the path of least resistance, meaning larger pipes, larger or more radiators on those pipes, larger vents will make steam favor those first and others will only get steam as the favored pipes/radiators are full and become more difficult for additional steam to get into them. By that time, the room with the thermostat will either be satisfied and the boiler will shut down or some of the other rooms will be too hot.
The correct way to pipe a boiler is to run one, two, maybe three (large house) Mains off of the Header and then each radiator is piped off of the Mains.
If piped as a parallel flow system, the mains are highest at the header and pitch downward as it travels along its path. Radiator run-out then pitch back towards the main that feeds the radiator. At the end of the main, there is a drop into a wet return so that condensate can get back to the boiler or the main continues, after the last radiator and turns back towards the boiler, pitching downward all the way an then drops into a wet return near the boiler.
On a Counter flow system, the mains are lowest at the boiler and rise along its path. The Radiator run-outs still pitch back into the main but condensate runs counter to the steam, in the pipe, back to the boiler but there is a Drip, for each main, just before the header, that drops to a wet return. That allows condensate to run down the drip rather than back into the header where hammer can occur.

steaminvt

Cautious optimism here. Spent a few hours pitching pipe. Started at the boiler and worked outward since the hammer seemed to originate in that area. Immediately found negative slope in that first 3' run before the downturn into the header! Raised at the elbow with a floor jack (see pic) hoping that I would have enough slope in the 'long run' to absorb raising up the 2 other elbows ahead of it. Thanks to Jughne's nail method, I was able to easily adjust pitch until I got downward slope along all the pipes. ( I modified the nail approach by pushing nails into the center of all the piping every 3 feet or so [closer on the short runs] to allow quick checking as I went along). So far I have warm started and nearly cold started with no hammer and the heat is traveling up the long run MUCH faster. If tomorrow mornings cold start is quiet, I will retrry ethicalpauls's 'remove the main vent' idea to see if heat gets to the problem rad even faster. As it stands, this rad did starting getting heat soon after the other rads. I will replace all the wood props with proper straps if all goes well tomorrow. TY to everyone so far.

ethicalpaul

That sounds promising!

Just to clarify though—the remove the main vent thing is just to see if steam is getting to the end of the main. You can’t run like that—steam will never go to the radiator if there’s not a vent on that fitting. It will just go into your basement

steaminvt

yes, I just want to see if the heat seems to travel faster to the back and justify a bigger main vent or doubling up on #1's

ethicalpaul

I like it. Great for testing if there’s enough venting

steaminvt

Silence! Cold fire this morning, no hammer, no ticking. I timed the progress of heat up the long run of the pipe to the back of house and will re-time sans the main vent.... If more venting is justified, is it feasible to make the hole bigger in the Gorton #1?

I promised some steam porn earlier. I will post in new thread.

Steamhead

steaminvt said:

.... If more venting is justified, is it feasible to make the hole bigger in the Gorton #1?

Nope. Get a Gorton #2. You'll need something like 8" of vertical clearance to install it though.

Hap_Hazzard

There's a reason the Gorton #2 doesn't use the same form factor as all their other vents. The orifice on a Gorton #1 is about the same size as the internal orfice where the float seats, so enlarging the external orifice won't allow it to vent any faster. To make a faster vent, they had to go with a different design.

steaminvt

TY. I will tee and add another #1 if need be. No room for a #2.

nicholas bonham-carter

A big mouth might fit in there and have the capacity of multiple G-1’s.—NBC

gfrbrookline

So if I read above correctly the previously slow venting main is approx. 40' long. A Gorton 1 vents a 10' main, a Gorton 2 is good for 20' and a Big Mouth is rated for appox. 50', if you have clearance issues I would go for the one Big Mouth or 5 Gorton 1's on a single sided antler. One Big Mouth would be easier but only if you have dry steam.

What size are your other mains? You want to make sure they are also vented well.

You also mentioned that you installed new Gorton vents on the radiators, what sizes dd you use? Hopefully nothing larger than a 5. If you vent your mains properly anything larger than a 5 will rob steam as it will act as a mini main vent.

steaminvt

NONE of the mains had a main vent when we bought the house. I added the #1 to the problem line where I saw a plug near the end. I did put bigger Gortons on the 3 ( 2 6's and a D on a rad that the previous owner said never worked) radiators on this line.
The down stairs uses 2 4's near the Tstat and the rest are 5's.

I may need to re-size if a bigger main vent on the problem line appears to be in order. I have not timed the movement of heat up the pipe with this vent removed, per ethicalpaul, yet.

gfrbrookline

You need to vent all of your mains not just the problem one. Venting the mains properly lets the steam distribute evenly in the basement so it can reach all of the radiators above evenly. What you are doing by only looking at the slow main is band aiding a problem, better to fix the entire main venting and address the root cause than a symptom. Since you have plugs there were likely vents there that were removed and should be replaced. The originals were likely undersized as that was available at the time and venting was not understood yet.

What size pipes and lengths do you have on the other mains. That will allow us to give you a recommendation for the other main vents you will need. It's not a science but a good starting point.

steaminvt

I agree. I was astonished (after reading D.H.'s tenets for steam) that there were none present. Only one other main line has a spot for one at the end where some piping branches off to head upstairs. There may be room for a #2 (about 20' run) after I remove that plug.
The other plug is located near the boiler in that tangle of pipes where another run starts (?).
Its possible there are other plugs stuck at the end of the other runs but they would likely be buried in spray foam where the foundation was replaced the rim joist got insulated.
For now, the other runs are sending steam to the other rads but the other rads will vent loudly if I'm trying to raise the house temp more than 6 degrees or so.
I can see from some fuel oil delivery history that the previous owner was going thru a lot of oil just to maintain heat while they were in FL for the winter.
No budget for reworking my steam pipes but would be happy if proper venting where access is available and balancing the rads from there would bring a little more efficiency. We do have a pellet stove for the main living area and a small wood stove in the kitchen in back.

Jamie Hall

Keep in mind that any vent is better than no vent on a main. It's nice if they can be at the end, or at least after the last radiator runout, but... if not... One possibility sometimes overlooked is to place a "main" vent in an accessible location on the last radiator runout. That usually works well, even if it is not ideal.

Get creative!

gfrbrookline

You mentioned raising the temperature degrees. Keep in mind single pipe steam likes steady temperature. You should not use setbacks greater than 2 degrees or you will wast a lot of money on fuel.

steaminvt

I am dialed in on the setback now. We were heating with the pellet stove (in room w/ t-stat) until I got a handle on the water hammer and I had to run it while to get other rooms & upstairs warm w/ the rads. House is maintaining temp w/ just steam at the moment. Now I will get the main vents done and try to balance the rads as best I can with the current piping. Will have more time this aft noon and tomorrow.......

Your comment does make me wonder if it is cost effective to use the programmable t-stat currently in place. ie we can have heat essentially idle (set real low) while we are away and it it will come back on like an hour before we arrive home. We can program all seven days with different cycles around sleeping and coming and going. OR, we can just leave it on all day at a reasonable temp like 67..

Will this be a more critical decision to make when our outside temps start falling to single digits?