Radiator rhythmic clunking

radiatorbanging2021

Hi everyone,

The radiator in our main bedroom have started banging loudly since the start of this heating season. We just bought the house this summer.

I discovered the steam valve leak under the hood and followed a Youtube guide to put some Teflon on and it seems to be fixed:
https://www.youtube.com/watch?v=4L5lmA7PGiQ

Then I did check the radiator pitch, make sure the valve is fully open, change the air vent from Varivalve to Hoffman 1A and use the lowest setting... the noise is reduced but we still have this rhythmic clunking:

https://www.youtube.com/watch?v=6XxTBYcYTpM

Also the Hoffman vent seems to make louder hissing noise comparing to the old Varivale

Appreciate any help in making it more quiet.

These are some pictures of the pipe in our basement, seems like we have 2 mainlines, but I only see one airvent in the pipe that leads to our bedroom.

Jamie Hall

Several things... I think the noise sounds like a water hammer. The vent hissing is from pressure -- which is too high. The pressure control needs to be dialed down to about 0.7 psi, though that may not help much...

The noise. The boiler piping may be giving you some wet steam, but whether or not it is, if it really is a water hammer (which is what it sounds like) you need to look at the pitch of all the pipes leading from the main to the radiator. The need at least a half inch in 10 feet pitch, and since I seem some copper and not much insulation more like two or three inches won't hurt.

neilc

agreeing with Jamie , dial the Ptrol down to the bottom, 0.5 cut in, and inside the cover, the white differential wheel set to 1, for a 1.5 cut out,

the water in the sightglass looks dirty,
consider draining the boiler and refilling, more than once,
let the boiler cool down first,

and cause dirty water,
has the pigtail been checked ?
they get gunked up and isolate, instead of protect, the Ptrol,
it needs to be clear breathing all the way back into the boiler so the Ptrol can see the boiler pressure,
with the boiler off,
pull the gage off and see if you can blow freely back into the boiler,
if not, disassemble all and clean or replace,
prime the pigtail with a 1/4 cup of water before replacing gage or Ptrol

radiatorbanging2021

Jamie Hall said:

Several things... I think the noise sounds like a water hammer. The vent hissing is from pressure -- which is too high. The pressure control needs to be dialed down to about 0.7 psi, though that may not help much...

The noise. The boiler piping may be giving you some wet steam, but whether or not it is, if it really is a water hammer (which is what it sounds like) you need to look at the pitch of all the pipes leading from the main to the radiator. The need at least a half inch in 10 feet pitch, and since I seem some copper and not much insulation more like two or three inches won't hurt.

The main pipe go right into the wall in the basement as you can see in the last picture. In that small visible segment I could see it does have some pitch, but all other segments are under the floor/inside wall so not sure how I can check/fix that. The radiator is on the second floor and the pipe are all under floor until right below the radiator.

dabrakeman

The banging or water hammer would typically be from some water collecting in a horizontal run toward the radiator that has a sag or is not pitched back to the boiler. If the radiator pitch is OK you can also try raising the radiator an inch or half inch or so (maintaining pitch). I use a 2x4 as a lever and just slide some shims under the radiator feet. Seems a little odd to me that the valve you fixed is so flush to the floor so maybe the pipes did get lowered at some time somehow??

To address the hissing you want to increase your main venting and set your pressuretrol at its lowest setting (0.5psi on that cut-in scale and the white differential dial inside the pressuretrol set at 1 (its lowest). This means the boiler will shutoff if it sees >1.5psi and kick back on when pressure reduces to 0.5psi.

You say you have two mains? I only see one with only one return pipe coming back to the boiler. Does the main split somewhere and then have a second extension back to the boiler we don't see? It looks like your main vent is on the end of the main extension as it loops back to the boiler. You can keep your main vents there but raise them up on a short extension and make an "antler" so you can just add vents alongside your existing one. If it is all on one main I would just add a Gorton #2 to your Gorton #1..

neilc

at that radiator,
see if it can lift up, carefully,
including lifting the supply pipe and valve with it, carefully,
a block of wood, and a length of 2x4, as a lever,
or a garden shovel, and wood block under rad columns, carefully,
can that supply riser lift up at all ?
and repitch the rad , , ,
looks like good pitch on the return pipe to the vent, and boiler,

EBEBRATT-Ed

What @neilc said above

neilc

Brakeman beat me to it , , ,

radiatorbanging2021

Duplicated comment

radiatorbanging2021

neilc said:

agreeing with Jamie , dial the Ptrol down to the bottom, 0.5 cut in, and inside the cover, the white differential wheel set to 1, for a 1.5 cut out,

the water in the sightglass looks dirty,
consider draining the boiler and refilling, more than once,
let the boiler cool down first,

and cause dirty water,
has the pigtail been checked ?
they get gunked up and isolate, instead of protect, the Ptrol,
it needs to be clear breathing all the way back into the boiler so the Ptrol can see the boiler pressure,
with the boiler off,
pull the gage off and see if you can blow freely back into the boiler,
if not, disassemble all and clean or replace,
prime the pigtail with a 1/4 cup of water before replacing gage or Ptrol

I have a feeling that the PSI reading is always at the below value whether or not the boiler is running - is it normal? Or it may be clogged as you said, will double check later.


I tried to drain the boiler but all the valves around the boiler and the surrounding pipes seem to be clogged - nothing coming out of them! Is there any way to unclog it?

dabrakeman said:

The banging or water hammer would typically be from some water collecting in a horizontal run toward the radiator that has a sag or is not pitched back to the boiler. If the radiator pitch is OK you can also try raising the radiator an inch or half inch or so (maintaining pitch). I use a 2x4 as a lever and just slide some shims under the radiator feet. Seems a little odd to me that the valve you fixed is so flush to the floor so maybe the pipes did get lowered at some time somehow??

To address the hissing you want to increase your main venting and set your pressuretrol at its lowest setting (0.5psi on that cut-in scale and the white differential dial inside the pressuretrol set at 1 (its lowest). This means the boiler will shutoff if it sees >1.5psi and kick back on when pressure reduces to 0.5psi.

You say you have two mains? I only see one with only one return pipe coming back to the boiler. Does the main split somewhere and then have a second extension back to the boiler we don't see? It looks like your main vent is on the end of the main extension as it loops back to the boiler. You can keep your main vents there but raise them up on a short extension and make an "antler" so you can just add vents alongside your existing one. If it is all on one main I would just add a Gorton #2 to your Gorton #1..

There is a white pipe which does get hot, and points toward the radiator in our living room so I thought it is a main pipe as well, is it not?

neilc said:

at that radiator,
see if it can lift up, carefully,
including lifting the supply pipe and valve with it, carefully,
a block of wood, and a length of 2x4, as a lever,
or a garden shovel, and wood block under rad columns, carefully,
can that supply riser lift up at all ?
and repitch the rad , , ,
looks like good pitch on the return pipe to the vent, and boiler,

I tried to lift the radiator by hand but it does not move at all. Will try again with some leverage...

neilc

radiatorbanging2021 said:

I have a feeling that the PSI reading is always at the below value whether or not the boiler is running - is it normal? Or it may be clogged as you said, will double check later.

No, not normal,
your gage is tee'd off above the pigtail, and also isolated as I suspect,
check and clean the pigtail, blow all the way back into the boiler,

radiatorbanging2021 said:

I tried to drain the boiler but all the valves around the boiler and the surrounding pipes seem to be clogged - nothing coming out of them! Is there any way to unclog it?

it's gonna get messy , , ,
open the valve under the sightglass fully, can you poke up in there with a small screwdriver, or stiff wire?
or really messy, unscrew the valve from the boiler and clean or replace it,
you have a second valve at the wet return / hartford loop,
might as well make a mess there also,
be ready for dirty HOT water,

dabrakeman said:

, , ,
You say you have two mains? I only see one with only one return pipe coming back to the boiler.

radiatorbanging2021 said:

There is a white pipe which does get hot, and points toward the radiator in our living room so I thought it is a main pipe as well, is it not?

that white pipe is your system main,
it should loop around and end up connecting to the other picture with the vent shown on that return, or main extension,

radiatorbanging2021 said:

I tried to lift the radiator by hand but it does not move at all. Will try again with some leverage...

firmly, but gently firmly

dabrakeman

Radiatorbanging2021 said: There is a white pipe which does get hot, and points toward the radiator in our living room so I thought it is a main pipe as well, is it not?

Unless after that split the line going toward your living room continues on a downward slope and then loops back to the boiler it is just a takeoff. If you do have two return lines ( continuations of the mains going back to the boiler) then you would have two mains each of which would need its own vent before it drops down to the wet return.

That radiator might be a couple hundred pounds. Nonetheless, use slow and gentle leverage. If it doesn't move with the amount of force you think should lift a couple hundred pounds then don't force it.

radiatorbanging2021

Thank you all, now I understand the near boiler piping, only one main it is!

Lurking around here I found @EzzyT seems to work on my area (Nutley NJ), sent him a message hopefully he can come helping us.

EzzyT

So I looked that this system and boiler and the basement was flooded about 2’. Due liabilities concerns I wouldn’t touch the boiler I would replace it. Plus the the overall reason why the issues are occurring throughout the system is due to lack of maintenance on the boiler, not enough main venting and there is zero insulation on all the steam system piping.

ethicalpaul

The OP might be able to find someone who will replace the gas valve and clean/inspect the burners

https://www.weil-mclain.com/news/servicing-flooded-boilers

radiatorbanging2021

Thank you all very much for your help!

I called the company that installed the boiler. They helped to unclogged the valves, change the eyes glasses, flushed it few times. The water is clear now and I could see the pressure reading moving when the system is operating.

As advised I also reduce the pressuretrol cut-in to around 1psi (tried 0.5 but then the boiler won't turn on again after being turned off by the pressuretrol)

Using a 25 inch pipe wrench and PB Blaster, I was able to remove the old main vent and replaced it with a Gorton v2 and a Gorton v1.



Using the same 25 inch wrench and plastic shims from HomeDepot, followed the advise here I was able to gently lift the radiators and supply valves. With that method I checked and re-pitched all the noisy radiators/supply valves in the house.

After all of that, all the banging noise is gone. Still some Hoffman 1A vents were making very audible hissing noise, so I replaced them with the old, cleaned Varivalves and they are much more quite.

Currently the outside temperature is 18F/-8C but it is warm and peaceful inside. I can put away the costly and dangerous electric space heater. Wife and kid are happy

Thank you again for your help! I also learned a lot from the "We got steam heat" book - great book, a pleasure to read.