gurgling in riser

gramcynyc

Major gurgling and hammer noise reduced, but still very much present in riser below the top (5th) floor radiator which is the last in the system. I just replaced the vent valve with a Gorton D and pitched it toward the riser. Also disconnected it to drain it of a good amount of rusty sediment. I don't recall it being noisy in previous years but its seldom occupied apartment and may have been off. The other three risers in the townhouse are not noisy.
Additional information: when I renovated the apartment last year I removed the radiator just next to it and capped off the pipe at the floor. It comes off the same riser 36 inches way, which is just next to the radiator left in place. Could this trap water that causes the gurgling in the riser below?

So now the tenant above can sleep well but I still need ear plugs. Any Ideas?

gramcynyc

actually no hammer noise ... just gurgling for full steam cycle

Fred

There is probably a horizontal steam supply pipe under the floor that has lost its pitch. If you can, you can try to raise that radiator up and put some wood blocks under the legs. Get it up a 1/2 inch to an inch and make sure the radiator is pitched towards the supply pipe (I assume this is a 1 pipe system). Also make sure the boiler presure is low. Sometimes too much system pressure can prevent the water from getting back to the boiler during the heat cycle.

nicholas bonham-carter

This sounds like a lack of main venting, and overpressure.
Have you access to the rest of the system to check the main venting, and pressure? If not, then maybe you can put a low pressure gauge on your capped riser.
Your modifications may have changed the pitch of the horizontal pipe under the floor, trapping some water in it for the steam to blow through.--NBC

gramcynyc

I checked the pressure in the system and it appears to be within the limits. The remaining radiator at the top of the offending riser is at the end if it. It is well pitched and vented with new D valve. There is a vent at the base of that riser in the basement and it too appears to be functional.

gramcynyc

As to the horizontal 36 inch pipe for the old removed radiator...that my have sloped away from the riser...could that be a cause?

Fred

gramcynyc said:

As to the horizontal 36 inch pipe for the old removed radiator...that my have sloped away from the riser...could that be a cause?

Yes

gramcynyc

I just pulled up that stub out of the floor as much as it can to pitch it back towards the riser. Still gurgling occurring through cycle

Fred

Is the other radiator pitched back towards that riser? What about the horizontal to it? You may need to raise that radiaator up to get some pitch on the horizontal as well. What about the system pressure? What is it running?

ChrisJ

What pressure is the system running?

The limits all depend on who you ask.

gramcynyc

I'll check the reading on the next cycle. I think the honeywell settings are 1 on one box and 2 on the other. The guy upstairs thinks it was quieter earlier in the season before I raised the output for the cold spell, so I just lowered it a bit. (grasping at straws?)

gramcynyc

sounds like what I'm left to check out is system over pressure, though I don't know why this would change on its own

Fred

gramcynyc said:

sounds like what I'm left to check out is system over pressure, though I don't know why this would change on its own

It could change because the pigtail(s) that the pressuretrols/vaporstats are mounted on are clogged with gunk or the pressuretrol itself has failed.

Abracadabra

slower vent on the radiator might be needed.

gramcynyc

I don't think a slower valve would help since the old valve would stick and probably be slower than the new D size I put in. Also the issue is the rattling occurs at the start of the cycle, and during the cycle, not at the end when you'd expect the steam to convert to water.

gramcynyc

the cycle at lower setting had less loud rattling.....is that a sign I'm heading in the right direction?

gramcynyc

thanks everybody....looks like its running at too high a pressure. Just saw it go up to 4 and I think it should top off at 2 or 2.5. I'll hire someone to fix it all next week. Its a bit outside my pay grade to do.

Fred

gramcynyc said:

thanks everybody....looks like its running at too high a pressure. Just saw it go up to 4 and I think it should top off at 2 or 2.5. I'll hire someone to fix it all next week. Its a bit outside my pay grade to do.

You should try to keep it around 1.5PSI tops. It probably is a clogged Pigtail.

gramcynyc

actually...there are two controls. a double that says main (set at @4) and diff. (set at 2) and the other single control set at 1psi. So if I see the pressure gauge go to 4...perhaps its not over pressurizing since the upper limit may actually be 4.

can I lower that limit to see if that helps?

Jamie Hall

Yes you not only can lower that limit,you should. Try setting it at a main of 1.5 and a diff of 1.

Fred

The Empire State Building runs on about 2 PSI. You want The MAIN to be at about 2, (I would try 1.5) and the differential to be at 1

gramcynyc

lol... on my way down to figure out how to do that...thanks

gramcynyc

I don't know why the plumber set it this high several years back nor why its causing an issue now

gramcynyc

alright...I lowered it to 2 with a diff of 1. It did shut down at 2psi so there is no gunk in the pigtails and the limit control works.
Still rattling but I'll wait a cycle or two since they are now short and perhaps the condensate hasn't fully returned.

Abracadabra

A slower vent on a 5th floor radiator will reduce the amount and velocity of the condensate being formed once the steam begins to enter the radiator. A better way to vent a 5th floor riser is to place a main vent on the pipe to quickly vent the riser, and then use a slow vent to vent the radiator. Since the steam moves into the the radiator slower, condensate is formed at a slower rate, which may help with your gurgling and hammer. Has anyone checked the supply valve to make sure that the disc is tight and not partially closing off the valve? which would create a situation with condensate not being able to return? I assume this is single pipe steam? Someone asked, but I didn't see an answer to that.

gramcynyc

it is a single pipe system. there already is a main vent at the bottom of that riser. I informed the tenant to keep the supply valve (which is new) fully open or fully closed. If too hot, I asked him to open the window...welcome to steam heat in manhattan.

still waiting for next cycle at lower psi setting......

neilc

don't forget what Jamie and Fred said,
you could still drop another 1/2 # on your cut out.

gramcynyc

ok...it still rattles but much less loud this time

Abracadabra

gramcynyc said:

it is a single pipe system. there already is a main vent at the bottom of that riser.

No... not at the bottom... a main vent at the top of the riser, along with a slow radiator vent.

gramcynyc said:

ok...it still rattles but much less loud this time

Rattling? I thought we were troubleshooting gurgling and hammering?

gramcynyc

but the radiator is at the top of the riser. tops off in a valve to the radiator. had been this way since installation without this problem. something changed this season. Last year I installed new floor, removed the extra radiator 3 feet away. Re-installed the radiator in its original position at the top of the riser (sunk into holes in new floor). Found the inflow valve leaked last year, so replace that. Found it too noisy this season and realized the radiator was level so I pitched it. Then it got so noisy and the hammering started. so yesterday I changed the vent valve which was sticky. I've lowered the amount of steam and now the pressure and still left with rattling for much of the cycle.

neilc

You kinda narrowed this down to the floor, valve, and other rad, that work.

post a picture of that rad, the vent, and the new valve,
you sure you have the correct valve, not holding back condensate?
and pitch ?
maybe fill the holes in the new flooring?

gramcynyc

it used to rattle and sound like sloshing water and hammering for only the day after I pitched the radiator with the old vent valve. I then changed the vent valve yesterday to a Gorton D since it at the end of the system. this vent valve has made the tenants life much better as it is nearly silent compared to the old hissing one. However, I'm still stuck with the rattle in the riser bellow that radiator.

the holes in the floor were needed to bring the radiator back to the level of the inflow valve at the top of the riser.

neilc

gramcynyc said:

something changed this season.

Last year I installed new floor, removed the extra radiator 3 feet away. Re-installed the radiator in its original position at the top of the riser (sunk into holes in new floor).

Found the inflow valve leaked last year, so replace that. Found it too noisy this season

and realized the radiator was level so I pitched it.

Then it got so noisy and the hammering started.

is that gorden d a fast or slow vent (I don't know),

and the rad is pitched to drain back down to the "inflow" valve, right?

gramcynyc

D is the largest (or fastest) designed for the end of the system.
Pitched towards the inflow.

ChrisJ

Is the pipe rubbing against wood or something and popping as it heats and cools, or rather, as whatever it's connected to heats and cools?

neilc

Abracadabra said:

A slower vent on a 5th floor radiator will reduce the amount and velocity of the condensate being formed once the steam begins to enter the radiator. A better way to vent a 5th floor riser is to place a main vent on the pipe to quickly vent the riser, and then use a slow vent to vent the radiator. Since the steam moves into the the radiator slower, condensate is formed at a slower rate, which may help with your gurgling and hammer.

might be worth a try slowing the rad venting.

gramcynyc

the noise I completely within the riser below the radiator during the steam cycle, not before nor after. It comes and goes a little during the cycle...if that helps

neilc

flip the vent upside down for one cycle and see if the noise stops,
no venting = no noises = ?source of problem?

gramcynyc

hmmm....place a faster vent valve pre radiator and a slow valve on the other side? I've not seen that before. Would be a major undertaking and I'd have to extend the pipe going into the radiator and drill new sink holes for the new placement of the radiator. I'd hate to do all that and find it didn't work. Still leaves the question why it was fin for 50 years, and not this year.

gramcynyc

I closed the inflow valve for one cycle and that sure stopped it! but no heat to his apartment. I have suggested doing that the rest of the winter and using an electric heater at night so we can sleep....I'd have to foot the bill though. (These are exposed risers in our bedrooms near beds)

neilc

No,
just put a slow vent on the noisy rad,

If flipping the vent over makes quiet then what Abra suggests may be your fix.

you might (try) put another main vent where you removed that other rad, (top of riser).

You said you had a main at the bottom of same riser,
is that good? and adequately sized ?

Vent mains fast, rads slow.