Singe Pipe Steam Heat Radiator Banging and Hissing

illka99

Hi All,

I live in a single family 2 story townhouse from 1905 with original steam radiators.

While the heating works great throughout the house, unfortunately, one of the bedrooms has a problem in that the radiator bangs pretty loudly for about 5 min, only at the beginning of a heating cycle. In addition, at the very end of the cycle, once it gets fully hot, it make an extremely loud hissing sound with a Gorton D until the cycle is shut off.

In speaking with a plumber, he advised that I replace the main air vent and I just installed a gorton #1. However, the problem did not improve. I ordered a Gorton #2, but it doesn't fit so I may not be able to install it

Can you guys make any suggestions besides swapping the Gorton D for a weaker valve to improve the hissing sound.

Attaching floorpan of my house for your reference. The problem radiator is labeled in red. It also happens to be the one furthest from the boiler.

Best,
Ilya

JUGHNE

The banging is most likely water hammer from the steam meeting some water in the pipe or radiator.
The radiator needs to slope back towards the inlet valve to drain back.

If that has already been done then perhaps raise the entire radiator a 1/2" under all 4 legs and retain whatever is creating the slope towards the inlet valve. The run out pipe under the floor may have sagged.
If may appear to have a pipe straight up from the basement but often has a horizontal pipe under the floor.

As far as the main vent show us a picture of current vent.
Also pictures of boiler piping, floor to ceiling.

Jamie Hall

And if you can get to the basement, check the cutoff pressure of the boiler. I'll bet it's too high.

illka99

Thanks Both. Please see photos attached of everything.

I have previously tried to pitch the slope of the loud radiator but it doesn't help.

delcrossv

If you twist that 45 below your main vent away from the wall, that should give you room for a larger vent if necessary.

JUGHNE's suggestion of raising the whole radiator a little is a good one. You have a pocket of water sitting somewhere in the line to that rad.

The boiler piping is "odd" but if the system is working aside from the last rad, it's probably not the source of your issues.

Is there any insulation on the main? I don't see any.

JUGHNE

Did you try to lift both ends of the radiator for that 1/2 block under all 4 legs and then put the wood circles under the end as they are now?

Have you ever cleaned the pigtail under the pressure control, sludge can keep the boiler running too long.

What does the pressure gauge show when it is up to full steam?

Show the lower piping on the left side of the boiler please, clear away so we can see all of it.

As for the main vent, you could remove the existing vent.
Add a nipple and 90. then add horizontal pipe (3-4") with another 90 pointing up.
Arrange to swing away from the wall and add riser as high as possible for the G2 to screw into and have clearance from the wall.

Great looking flooring and trim, BTW.

illka99

Thanks again to you both for taking a look and your advice.

I don't quite follow. So you're suggesting that I place the wood circles under all 4 legs instead of only 2? Or are you saying that I should have two people try to lift the entire radiator up on both sides, and THEN place the wood circles under all the legs?

To answer your questions:
1. I don't see insulation on the main going from boiler (back of house) to front of the house along the basement ceiling. This is how it was when I bought the house.
2. I've drained the water from both the left side of boiler and right side. There is some brown water, sludge in the very beginning usually.
3. I will run heat tonight and let you know the pressure when in full steam

Requested photos attached of boiler left side piping.

With a Gorton D, if there is SUPER loud hissing at the end of the cycle, when rad is fully hot, what is that a sign of usually? Too much air in the system which can only be improved with a G2 on the main?

delcrossv

With the D, at the end of the cycle is air going in? I.E. you don't feel anything blowing out of the vent? If the rad is full of steam, the vent should be closed. Might just be a bad vent.

To your other question, yes, raise the whole radiator a half inch(Easier to do it one side then the other) and re insert the discs on the vent side.

illka99

delcrossv said:

With the D, at the end of the cycle is air going in? I.E. you don't feel anything blowing out of the vent? If the rad is full of steam, the vent should be closed. Might just be a bad vent.

At the end of the cycle with the D, it starts to hiss SUPER loudly (10/10 loud) and I think there is hot air/steam blowing out. I tried to touch it and couldn't. So I don't think think the air is going IN. Unless that happens as soon as cycle ends?

Gorton rep told me to post here to make sure there isn't a vacuum situation. Is this what you are alluding to?

delcrossv

No steam should be blowing out of the vent. Get another one (Maid O Mist are cheaper) and swap it out.

If it's really screeching, I'd guess there's inadequate venting elsewhere.

As the steam condenses into condensate, air has to be reintroduced into the system, but that's not what you're describing.

JUGHNE

For the radiator, you are trying to pull up the pipe that is connected to supply valve.
Get 4 blocks that are about 1/2" thick, more circles if that is what is handy.
Get a 3-4' long 2x4 for a lever, then a couple of 2x4 blocks for fulcrum for your lever.
Your lever goes under the radiator on the valve end. The fulcrum goes on the floor under the lever close to the rad maybe 6" away.

As you push down on the long lever, see if you can pry up the valve end of the radiator very slowly and carefully.
If it comes up easy and high enough for the 1/2 blocks put one under each of those legs.
Then move your lever assembly to the rear, raise that up for 2 blocks under each leg on the rear.

This may get rid of any water sitting in the pipe that may be under the floor.
If it only goes up a 1/4" that might be enough. Still maintain the slope towards the inlet valve.

illka99

At full steam the pressure gauge 1psi. Could this be? I was very surprised it was so low.

illka99

JUGHNE said:

For the radiator, you are trying to pull up the pipe that is connected to supply valve.
Get 4 blocks that are about 1/2" thick, more circles if that is what is handy.
Get a 3-4' long 2x4 for a lever, then a couple of 2x4 blocks for fulcrum for your lever.
Your lever goes under the radiator on the valve end. The fulcrum goes on the floor under the lever close to the rad maybe 6" away.

As you push down on the long lever, see if you can pry up the valve end of the radiator very slowly and carefully.
If it comes up easy and high enough for the 1/2 blocks put one under each of those legs.
Then move your lever assembly to the rear, raise that up for 2 blocks under each leg on the rear.

This may get rid of any water sitting in the pipe that may be under the floor.
If it only goes up a 1/4" that might be enough. Still maintain the slope towards the inlet valve.

Thank you! I will try this

JUGHNE

Be careful with that CI rad, it is heavier than one imagines and top heavy.

The 0-30 gauges that come with boilers are notoriously inaccurate, another thing on your to do list is clean the pigtail under the control.

illka99

Unfortunately I don't think I will be able to install the G2 and will need to call in a plumber to alter the piping to make room for it.

How necessary is the G2 in your opinion given my overall situation?

ethicalpaul

In my opinion a working Gorton #1 is a very good main vent. If you are really curious, you can start a call for heat when the system is warm, start a stopwatch on your phone when you feel steam in the header, and tell us how long it takes before the main vent closes upon steam hitting it.

If it's more than 2-3 minutes you probably don't have enough venting.

ChrisJ

Please don't use WD40 anywhere near a steam system unless you plan on skimming.
I even run taps dry.

Chris_L

If the only time the radiator vent is hissing is when the radiator and vent itself are hot, changing the main vent is not going to fix that. As others have said, it sounds like the radiator vent is not closing completely.

I too would suggest a Maid O'Mist vent--one with interchangeable or adjustable orifices. (Slowing down the venting might help your water hammer.)

Unless the riser to the radiator is exposed in the room below, you have to have a some horizontal piping. You need to determine if the water hammer is there or the radiator itself, and adjust the pitch accordingly. (That could mean tilting the radiator forward or backwards, not merely toward the valve.) If you have access to a thermal camera, you should be able to see the hot steam pipes in the wall or ceiling.

(I don't think having a 1" radiator valve is necessarily a problem. Nearly all of mine are 1" bushed down at the radiators, and there is no banging. These kinds of radiators always retain some water.

delcrossv

Normally true, I did have one rad (also at the end of the line) that sounded like a washing machine. Going full size 1-1/4 to a 1-1/4 valve and using a close nipple and reducer to 1" (vertical) for the riser cured it with a good deal of pitch

It was also a tall 2 column like the OP's. Seems those need a lot of space for steam to get in and push the condensate out. Initially, they condense like crazy.

ChrisJ

tommay said:

Chris J, do you really think a little squirt of wd40 in an air vent is going to foul the entire system? Squirt it in, shake it up, empty it out. All you have to do is look at the picture of the radiator and see it's pitch is minimal when using the baseboard behind it as a guide. Older house, settling floors....if the one inch pipe is 1/8 " above the bushing outlet, a little bit of water is going to puddle if the radiator is level or pitched backwards slightly. She says it only bangs for few minutes....so just a little bit of water.

Yes I do, ergo why I commented.
Especially if you do this to every vent in the system.

Gsmith

try changing the Gorton D vent on the problem radiator for a slower one. I prefer the Ventrite #1 which is adjustable (by turning a dial). Sometimes if you vent a radiator too fast, especially one with marginal slope in the radiator or radiator feed pipe the steam comes in too fast, creates a lot of condensate which the steam can't get easily past and causes the banging. It's a cheap fix if it works, suggest giving it a try, with an adjustable vent you can somewhat balance out how much heat the radiator produces against how much noise it might make.

illka99

Chris_L said:

If the only time the radiator vent is hissing is when the radiator and vent itself are hot, changing the main vent is not going to fix that. As others have said, it sounds like the radiator vent is not closing completely.

I too would suggest a Maid O'Mist vent--one with interchangeable or adjustable orifices. (Slowing down the venting might help your water hammer.)

Unless the riser to the radiator is exposed in the room below, you have to have a some horizontal piping. You need to determine if the water hammer is there or the radiator itself, and adjust the pitch accordingly. (That could mean tilting the radiator forward or backwards, not merely toward the valve.) If you have access to a thermal camera, you should be able to see the hot steam pipes in the wall or ceiling.

(I don't think having a 1" radiator valve is necessarily a problem. Nearly all of mine are 1" bushed down at the radiators, and there is no banging. These kinds of radiators always retain some water.

Actually there is an exposed vertical riser below this radiator. I can hear the banging in the riser slightly too. Not sure if it's coming from the radiator or piping.

illka99

Gary Smith said:

try changing the Gorton D vent on the problem radiator for a slower one. I prefer the Ventrite #1 which is adjustable (by turning a dial). Sometimes if you vent a radiator too fast, especially one with marginal slope in the radiator or radiator feed pipe the steam comes in too fast, creates a lot of condensate which the steam can't get easily past and causes the banging. It's a cheap fix if it works, suggest giving it a try, with an adjustable vent you can somewhat balance out how much heat the radiator produces against how much noise it might make.

Thanks. I will try this. I should also mention that this has historically been a problem radiator in that it's also the coldest room in the house and the last radiator to get warm. That's the reason I put a Gorton D on it.

illka99

I swapped the Gorton D for a Gorton C last night but the loud hissing sound once radiator got fully hot towards the end of the cycle was still super loud and woke us up. There is defiantly hot air coming out. I burned myself checking. At this point this is a much bigger problem than the water hammer.

What do you all suggest? Worth it to put a Gorton 2 on the main?

ethicalpaul

No. I suggest the same as the first couple responses. You have water collecting in a low spot probably in the supply to this radiator. You have to find it and correct it. Venting won't fix this.

LS123

By the way also make sure that where you connect the vent on rad is really secure and no pressure leaks. I had a one vent constantly hissing few drops of water coming out of the vent... bought a brand new identical vent and it was still hissing... then I realized threads on the rad was rusted. used very small amount of blue pipe dope and secured the vent... Hissing went a way.... As per @ethicalpaul you should rise the radiator to prevent any old sagging vertical pipes under floor / wall etc. The same rad I am referring to caused water hammering or banging last heating season. Once it was safely, and carefully lifted and pitched, hammering stopped. I had another person help me out with the lifting and the rads I have are not as tall as your rad. Also be gentle if you chose to lift it.... I am guessing most pipes you have may be original (may be.) Always good to have another persons help with tall rads...

LS123

@illka99 ** I mean horizontal pipes....
Also insulation of steam pipes in the basement, and insulation of basement to keep it from air leaks probably a good idea... will help the steam system to work more efficiently and save some money on fuel over time....

Lance

If your problem is not resolved and home improvements have been made i would suspect a trap in the pipe exists or an obstruction in the pipe. I had a client move a radiator once and they trapped the pipe to get under some structural beam. When valves break pieces drop down. at some point the radiator may have to be removed to check the pipe.