Water hammer

HeatingHelp

This discussion was created from comments split from: Balancing One-Pipe Steam Systems.

jb802

I have one pipe steam system. Just moved into the house and didn't know the water hammer existed until we turned the heat on a month ago. It's loud and frequent. The near radiator is the hottest and pretty quiet. I adjusted a valve on the biggest and farthest radiator from the boiler in an attempt to balance. That valve has a very easy to see 1 - 8 setting which I can twist to a setting, I have it at 8, fastest, and it seems to remedy the water hammer on that side of the room/house. Since doing that the hammering seems to have changed locations. The other radiators have a different valve with a 1-10 setting but I don't know which direction I am going in. I can hear the steam release but still do not know where the setting ends up (1-10). The water hammer has now adjusted to the next farthest radiator in the kitchen. It hammers but doesn't really get hot. This system has not been serviced in awhile, should I replace the valves on the radiator? I am going to insulate the pipes and re shim the radiators to help with pitch. Are there any other suggestions for this hammering?

neilc

Post a picture of the rad, both ends, the valve, and what I think you're referring to, the vent.
Also want to see the boiler, one picture floor to ceiling showing the boiler and the pipes above.
What's the boiler pressure set to?
should be as low as you can go.
What do you see on the pressure gage while it's firing?
since I think you have vents, the valve at the other end should be fully open, anything less and you get hammering.

BobC

Everything @neilc mentioned plus go over any horizontal pipe you can reach and make sure it's all sloped so water can drain back to the boiler. Also look for dips in the piping where water can collect, stretching a string along a segment of pipe will highlight this.

Bob