Seeking help: bedroom radiator LOUD water hammer

philosurfer

Hello,

I'm renting a very old house in Western Mass. The property has a steam heat system with one-pipe cast-iron radiators and a natural gas boiler. All of the radiators in our place work well. There are occasionally intermittent ticks (which I recognize as pipe expansion sounds) that originate in the basement and are audible from the first floor. Besides that, a couple of the radiators infrequently produce very faint water hammer sounds. In the main, for its apparent age and condition, the system is surprisingly auditorially unproblematic (though of course, I am aware that, under perfect circumstances, it would operate virtually silently). All of the radiators are level and none are pitched with shims.

Now, there is one very annoying exception to all of this, and of course the exception is the radiator in one of the occupied bedrooms. First of all, this radiator is the only one in the house that is pitched at all, and it is pitched slightly towards the intake/outake pipe (see the photo that I've attached). I don't have a proper level on hand but I recently had the system serviced to start the winter (the landlord's plumber came by and opened all the radiators fully, replaced something on the boiler (I think a release valve?), and put in new vents on many of the radiators), and he ensured everything was level. He also checked the pitch of the pipes in the basement and thought they were pitched appropriately.

Beginning this winter, we suddenly hear a VERY LOUD water hammer coming from this radiator in the bedroom. It BOOMS as the system begins to heat up and when it starts cooling off. The plumber thought he might've fixed this with the new valve, but nothing has changed.

I'm certain it's water hammer and, further, its point of origin appears to be in the radiator and not in the pipes downstairs, but who is to say. The radiator is fully open for one thing, and I don't think the pressure is too high (see the photos). I've tried to pitch it even more, but that didn't help. I was really careful not to pitch it too much more, as I didn't want to cause any further problems, so it's possible I didn't raise it sufficiently.

There is also pipe expansion in that same bedroom's wall, but that is connected to a pipe that feeds into and out of an upstairs radiator as best I can tell—however the contracted plumber thought the pipe expansion was water hammer and he thought he fixed that too by replacing the valve on that one problematic boiler… I've read We Have Steam Heat (I have so much respect for the art of steam heat now) and done extensive research on this forum. The contract plumber appeared decently knowledgeable, and I could easily be wrong as ultimately I'm no expert. Anyhow, the main issue is the LOUD hammer; the pipe expansions we can live with for now. I'm attaching as many photos as I can.

Lastly, two things. I called Charles Garrity Plumbing and Heating in Springfield and he suggested I post here first. Finally, I have CO alarms in the basement near the boiler and in the bedroom.

Thank you all a million… You have no idea how helpful your advice is to so many like me who have just been lurking on these forums.

Jamie Hall

Try raising BOTH ends of that radiator about an inch and see what happens.

BobC

I find a 2x4 and a block of wood allow you to gently lever a radiator up without much effort and minimum strain on the old pipes

Bob

philosurfer

Wait a second, that last picture in the photo series. The boiler is off screen to the RIGHT, but that middle pipe, which feeds the hammering radiator, is pitched slight at the joint to the left (you can see it leaning on the bottom pipe). I wonder if I simply raise that up a tad, maybe it would fix water hammer?

mattmia2

Try turning that vent to its slowest setting. Even the slowest setting on a vent rite is pretty fast if i recall, might need to put a slower vent on it.

mattmia2

What vent was on the radiator before?

Also it looks like the dry returns all connect together at the boiler above the water line, that is incorrect and can cause a number of problems but might be sort of ok.

Jamie Hall

https://forum.heatinghelp.com/discussion/comment/1876503#Comment_1876503

It might indeed. In fact, that might be the whole problem…