Inlet valve steam radiator issue

NFER · November 2020

Hello,
in one pipe steam radiator, the inlet valve is leaking air and steam with a very high pitch. The radiator is in the bedroom and the noise is waking us up. I have located the leak point in the picture.

What can I do? Is there any way to seal that joint?
thanks!

nicholas bonham-carter · November 2020

Over pressure must be doing this-can you check the pressuretrol settings, and the pigtail?—NBC

Jamie Hall · November 2020

And i that doesn't help ^^^, in theory you can unscrew that bonnet. In theory. And make sure the mating surfaces are clean and true and screw it back together with a little -- a little! -- pipe dope on the threads and mating surface.

May be much easier said than done...

NFER · November 2020

Thanks. I will discuss the pressure with the landlord. Lower pressure should save him money, right? Is there any disadvantage of lower pressure?
I just showed a video of cleaning and sealing the valve. It is out of my capacities. Can I seal that point with high heat silicone?

Lard · November 2020

Silicone just globbed on it will not end well.

I agree that the real fix is removing the bonnet and cleaning the mating surfaces, then reassembling with a bit of sealant (pipe dope or anaerobic sealant). Those bonnets can be very stubborn, so you may or may not have luck getting it apart.

I also agree that the pressure is too high. A leak like that should not make any appreciable noise at proper pressure. Lower pressure will save fuel since you are not burning to compress the steam. If it is cranked up to compensate for other issues, there may be a can of worms lurking in the piping.

NFER · November 2020

What is the recommended range of maximum pressures? Any other parameter to check in the boiler?

NFER · November 2020

The pressure was limited to 5psi. We tried with 2psi and the radiators on the top floor were heated only 1/3. I live in the top floor of a 4 story building. The raiser vents were venting correctly and the radiators with Gorton D as well. But it just stopped.
do the boiler suppose to start again when the pressure is lower than “diff”?

What do you think we should start checking? Main vents?

Jamie Hall · November 2020

Increasing the boiler pressure for steam is not the way to get more heat on upper floors. Improving the venting is. Even major skyscrapers get by very nicely, thank you, on 2 psi.

Make sure the boiler cutin is less than 1 psi, with a differential of 1. The boiler will cut out when the pressure is more than the cutout plus the differential -- in the plain grey box with one scale type of pressuretrol. The other type -- with a clear cover, the main scale sets the cutout pressure, and the boiler will cut back in when the pressure is less than the cutout minus the differential.

Now with the pressure correct, if some radiators -- or floors -- are not heating fast enough, you need to proceed in three steps on your type of building. First, make sure there is adequate venting of the mains in the basement. Second, you probably need riser vents -- vents at the tops of the risers -- and it is almost impossible to vent risers too fast -- though it is important that all the risers be vented equally. Then, and only then, start playing with the radiator vents themselves, and it is much more satisfactory to start by slowing down radiators which are faster, rather than trying to speed up radiators which are slower. You need also to remember that any change in venting will affect the way the whole system operates.

Dave T_2 · November 2020

Whether you can dial down the pressure or not, the leak will still be there, although the noise may stop. As suggested disassemble and clean the mating surfaces BUT I would suggest teflon tape as the sealant when reassembling.

Neild5 · November 2020

I have a leak like that on one radiator, it will whistle the whole time the system is running, but at least it is not in the bedroom. The max pressure is 17 oz, I have a new Marsh valve delivering on Friday so Saturday it will be installed.

NFER · November 2020

More questions:
if the thermostat is in the bottom floor (Landlord apartment) and supposed to be hotter than the top floor coldest room, any tip to get uniform temperature in the building?

This is a picture of the boiler with two controls. How does it work? Is the clear one just for safety?

ethicalpaul · November 2020

They’re all for safety 😅

but the left one is a backup to the right one that requires a manual reset. Mandated by code in a multi-unit residence I understand.

the right one is set correctly. The cut-in is displayed. Added to that is the setting of a dial inside, typically set at “1” added to the front value so: it cuts out the boiler at about 1.5 psi and lets it go back on at .5 psi

to get more heat upstairs the radiators near the thermostat have to be slowed, and/or the system’s main venting may need improvement

nicholas bonham-carter · November 2020

There is a difference between working main vents, and vents of adequate size to enable all the air to get out quickly.
Inadequate venting uses more fuel, Every heating cycle, to squeeeeeze the air out of constipated little Vents.
Your landlord may be concerned about Fuel economy, and might like to correct this.—NBC

STEAM DOCTOR · November 2020

@NFER. Back to the original point. There is a leak. A decent sized pair of pliers will get that bonnet off. Not hard. Wrap a few layers of blue monster tape. Works like a charm. Speaking from experience.

NFER · November 2020

Thanks! Does the tape go around the joint outside or inside?

STEAM DOCTOR · November 2020

Inside. You want the tape to squish where the two surfaces meet.

NFER · November 2020

The system is controlled by a Heat-Timer system. No thermostat inside the building. Landlord thinks the timer is bypassing the first pressuretrol. We opened the box an the differential was at 2 and lowered to 1 (is the number in the front right?).
What can we do if the grey pressuretrol is not doing anything?

JUGHNE · November 2020

Can you actually see the pressure gauge move with pressure increase? And is it zero when off for at least 15 minutes.

neilc · November 2020

NFER said:
The system is controlled by a Heat-Timer system. No thermostat inside the building. Landlord thinks the timer is bypassing the first pressuretrol. We opened the box an the differential was at 2 and lowered to 1 (is the number in the front right?).
What can we do if the grey pressuretrol is not doing anything?

1, check the pigtails for clogged,
2, know the wiring is correct, that the Ptrols are in the loop, with the heat timer

NFER · November 2020

Update:

check the pressure this morning and pressuretrol works: cut off 1.5 and kick in 0.5. But the valve still leaks. We will have to call a plumber.

I also went around the basement and notice that:

There are 2 mains coming out of the boiler: 1 Is 20 ft long with no insulation out of the boiler room and no vent. The second one is very long and it splits in 3. The two ends below the landlord apartment are longer and have insulation and vents (gortons I think). The one below my apartment doesn’t have insulation and vent. Now I understand why my bedroom radiator is venting the entire world, the apartments below have the radiator valve close to avoid the noise.

Is the insulation required? The basement is warmer than my apartment
what could be a very rough cost range of adding two main vents in nyc? How long could take to do it?

I am learning a lot. Thanks all

Dennis · November 2020

As a tenant, you could purchase some rainbow gasket material and attach with a stainless steel hose clamp.

If in theory you were to hire someone with the skill to disassemble the valve (in summer when the heat was not on) clean the mating surfaces apply a generous amount of teflon tape and dope on the treads and tighten, or my preference clean the surfaces, flux and apply solder the repair would in fact be permanent.

Examining the photo the valve has been removed in the past as evidenced by the coupling at the floor level. I'd replace the valve once again, in most cases this will require the replacement of the union entering the radiator as well. There's a trick to removing that part of the valve.

NFER · December 2020

Update: With a 18'' pipe wrench I was able to tight the bonnet. No more leaks so far. Thanks all for your help.
Now the main are insulated and steam comes faster and drier (I think).
However, the main to the bedroom and office in the north facade doesn't have a vent. The office has a riser without radiator with a 1/8'' vent at the top (Gorton D). I was thinking of increasing the venting capacity replacing the Gorton with elbow + nipple + tee + 2 varivalves I already have. What do you think?

The purpose is to get steam faster to the bedroom radiator because that room is very cold, takes a lifetime to get the steam and I want to get ride of using the space heater.

Landlord wants to add the main vents but it could take a while.

mattmia2 · December 2020

How is the vent attached? It would work better to use a larger adapter if there is a bushing or reducer you could remove and put a larger vent on directly, but a couple vents on 1/8" pipe is better than nothing.

NFER · December 2020

This is the riser with the Gorton d

NFER · December 2020

What is the best material for the fittings, brass or black iron?

ethicalpaul · December 2020

I'd use iron. But before you go to all that trouble, remove the vent, then put it back on when steam gets there, and see if that changes the timing of anything.

D is pretty large. It's the same size as a Gorton #1 main vent I believe. It would be a drag to do all this for no gain.

NFER · December 2020

I did that test and it helps. The other reason to add more vent capacity is that this riser feeds the bedroom radiator which is making some hissing and water noise (no banging). I checked the radiator pitch, lowered the pressure and still have that noise.
I added a danfoss TRV (already have it) with vent #5 to reduce the noise and radiator condensation. But when boiler shutoff the TRV vacuum breaking is making a huge suck in noise because there is no vents in the main I think. And that is why I tried this path with 3 o 4 #D vents.
What do you think?

ethicalpaul · December 2020

Sounds like you've done your homework!!

I'd still be wondering what is making that water noise if the pitch was checked but I'd say carry on

NFER · December 2020

I tried everything with the radiator: increase the pitch, rise the front legs, put plastics under the legs to get ride of the expansion/contraction noise (and it worked!!!), adding insulation to the main pipes....Everything except change the inlet valve and adding vents to the main.

But before that I want to add more vents to riser and see how it goes. If I can eliminate the TRV vacuum noise and sleep that would be enough.

BobC · December 2020

If there is any hirizontal pipe inder the floor it could be out of pitch. Try sliding 3/4 to 1" wood under all 4 legs and see if that helps.

Bob

NFER · December 2020

I did and there was a leak at the supply valve because of the rotation at the joint between radiator and valve. So it was no good and I lowered the radiator.
I tried tonight a Gorton #4 and the water noise disappear. It takes forever to get it full hot. It works for long cycle but in the evening cycles I get 50% hot.
Still working on the riser vent. More capacity will give more time to this radiator.
I was checking the venting charts to see if there is any thing between Gorton #5 and #4. Hoffman style vent is not an option because I hate the click clack sound. Do you know any other vent?

Vent fast mains (and risers!) and slow radiators

Inlet valve steam radiator issue

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