Need help. Steam heat. a couple of the radiators are knocking loudly..

[3Hotdogs]

Been going on since the freeze. I know that hot water, circulating can have banging radiators whee they get filled with water that has to be drained.

Any ideas?

[Tetrachloride]

1. I like wikihow

its been 22 years since i dealt with those radiators

possible links : https://duckduckgo.com/?q=wikihow+draining+steam+radiators&t=iphone&ia=web

[marble falls]

2. Water hammers, happens when too much steam gets condenced at bends in the plumbing ...

... there can be a pet cock at the bottom of the radiator, or in newer systems somewhere around the the the plumbing coming out of the boiler. Don't open it more than enough to get water to drain, remembering the steam is 212F or a bit more. Wear a glove.

[CentralMass]

4. Steam has something like 10x the caloric value of boiling water. Be very careful w/steam.

[marble falls]

5. Old Machist Mate here, who worked around high pressure steam in Naval propulsion ...

... systems. You have no idea how conscious I am around steam.

[CentralMass]

6. +1

[NBachers]

3. Put a level on top of the radiators and make sure they are tilted slightly toward the floor valve.

ALSO- Make sure the floor valve is all the way open. Here are the reasons:

1. Tilting the radiator slightly toward the floor valve allows the condensed water in the fins to drain back into the system. It doesn't need to be tilted much, just enough for the bubble to register. Otherwise, the water condensed into the fins gets pushed around by the steam and can cause banging.

2. Make sure the valve on the floor is open all the way. Trying to control the temperature by closing the valve part way only constricts the return water opening. It won't do anything to stop the banging.

If that doesn't work, there may be some problems with the return water pipe not being sloped properly, or filled with scale. Or, there may be connections near your boiler that are clogged with scale, impeding the flow of water. If the first two don't fix it, it may be time to trace the return water pipes to make sure they're flowing downhill, or have the connections at the boiler checked for clogging.

[NJCher]

7. Mine are knocking

Last year I had the Pseg over to look at it. They drained the water, refilled it, and told me it wasn’t a big deal.

The knocking isn’t too loud, though.

[Warpy]

8. That's my take, also, kind of comes with the territory

or did in every place I lived in that had steam heat. Unless the noise is really new and really alarming, chalk it up to the fact that the radiators might not be draining fully between the times the heat comes on in such cold weather and you're getting hot steam exploding into cold water.

Some knocking is absolutely normal as the metal in the radiators expands because that nice heat comes from really not steam.

[NJCher]

9. that was hilarious! Speaking of the arts and radiators....

I will have to keep track of this video to show my radiator buddy repairman if he ever comes back.

I loved how they built the "clang clang" of the pipes into the dance routine.

My radiator buddy repairman was someone I called when we first moved into this house decades ago and didn't know anything about radiator heat or how to handle it. So this guy comes over and raves about radiator systems and in particular my natural gas boiler and beautiful black, shiny radiators in every room. He went room to room, checking them and saying radiator heat was the best heating system, etc. He explained all the other heating systems and to hear him tell it, radiators were heaven on earth.

Anyway, he had to come back a few days later with a part, so in the meantime, I went on my literary databases and looked up poems about radiators. I was teaching poetry at the time. i found 11 poems about radiators!

I copied and pasted them into book-like form and gave it to him when he came back. He simply could not believe someone would do something like that for him. We read a few of the poems while he was here and I just knew he was going to treasure that homemade "book."

[Warpy]

10. Too funny, and I think he's right

Radiant heat, whether from radiators or wood stoves or whatever, are best, IMO. I've always frozen with forced air heat, hate it.

Right now, it's air heat via heat pump but it's not as bad as oil or gas forced air, for some reason, probably because the vents are up high instead of down near the floor where they invariably sent a draft down the back of my neck. This blows the stratified warm air across the ceiling and down toward the floor instead of blowing the cold air across the floor and up to the ceiling.

Hot water radiator systems were OK as long as I remembered to bleed the air out of the radiators every couple of days. Steam radiators were the best. The place just got warm and stayed that way. I didn't care about the clanks and hisses.

Glad you enjoyed the routine, the dance routine was the best one I found.