How to stop loud clicking (popping?) sound in 2 second flr radiators, source is in the radiators.

davevarga

I have a 100 year old house with steam heat. Single pipe to each radiator. The problem is that on the second flr, two of the radiators have loud clicks! as the radiators heat up. Maybe once every ten seconds. The source of the clicks is definitely inside the radiators, my ear was right next to them. It is not a vent based phenomena as I can remove the (new) vents and the clicks keep happening. The valves are fully open. There are no water leaks under the radiator. The radiator is pitched correctly down towards the pipe. The feet of the radiator can slide on the floor should there be slight expansion. Any ideas? Maybe I need to tighten the tension rods on the radiator? I very much hesitate to do that. thanks...

ImYoungxD

Probably pipe/wood expansion.
Cut pieces of the plastic milk jug and put them under the foot of the rads.

Fred

If it's a metallic pinging noise, it is likely expansion of the radiator sections. You can try tightening the tie rods a little (not too much) and make sure they are equally tightened and see if that fixes it. Do one and if that fixes it and the second one has the same sound, do the same on that one.

Jamie Hall

But don't overtighten those rods! Particularly if the radiator is cold when you do it. When the radiator expands it is very possible to either break the rod or strip the nut off the end -- and then you do have a problem.

davevarga

Hi, based on the sound it makes I am not thinking this is the solution but I will do it anyway tonight just to eliminate it as a possibility. Thank you...

nicholas bonham-carter

What vents are on the radiators in question?
Overly fast ones may cause them to heat up so quickly as to make this noise.
Try slower vents just as an experiment.—NBC

davevarga

The vents are indeed fast as if they were not, the 2nd flr radiator would not heat sufficiently to heat the room. Fred and Jamie, I would need a guaged torque wrench to tighten the rods ever so slightly and evenly?

nicholas bonham-carter

Generally, we advise fast venting on the mains, using a Big Mouth vent(s), and slower radiator vents. The optimum venting backpressure is 2 ounces, and this fills all the supply pipes before steam begins to rise up in the takeoffs on its way to all the radiators at the same time. This gives you better balance of temperatures throughout the house.
It’s possible for aggressive radiator vents to allow steam in so fast as to close the vent before all the air has been pushed out.
If you had a radiator full of steam at the top, and the lower half full of air, that temperature imbalance could cause uneven and noisy expansion. If you don’t hear the clicking during cooling down, it’s because the temperature change is so gradual.—NBC

Jamie Hall

On the rods. The approach I use which, so far, has worked well, is based on the realization that all the rods are supposed to do is to prevent the sections of the radiator from gradually creeping apart as it heats and cools. Therefore...

If I take a radiator apart, or in your situation the radiator is already assembled, I use a couple of nice big pipe clamps, top and bottom, to finish pulling the radiator together when it is cooled. You can really reef up on those puppies. Then I make sure the tension rod threads are clean -- the nuts spin easily by hand on and off. Then, with the radiator cold, I install the nuts hand tight (well, finger tight) and then take them up about a quarter turn to half a turn with a wrench. That's it.

Fred

What vents do you have on these radiators? Is the clicking coming from the vents? If they are Hoffman vents and relatively new (within the past 2 years), Hoffman made some change in their vents or the metal housing and they do click/ping as the bottom of those vents expand and contract. They will do that for about a year or so and then quiet down.

ChrisJ

Fred said:

What vents do you have on these radiators? Is the clicking coming from the vents? If they are Hoffman vents and relatively new (within the past 2 years), Hoffman made some change in their vents or the metal housing and they do click/ping as the bottom of those vents expand and contract. They will do that for about a year or so and then quiet down.

My Hoffman 1A's clicked pretty loud back in 2011. Are they even worse now?

@davevarga Can you post a youtube video of the problem? That would make it much easier.

Fred

@ChrisJ I don't know if they are worse. I had a stock pile before 2011 and didn't run out until a couple years ago. They can be pretty loud. They quiet down but it takes a year or so.