Help! I rent in an old apt. building and the radiator in my room sounds like someone’s banging on it with a hammer every time the heat goes on. I’ve looked for a bleed valve but can’t find one. This particular radiator has two pipes leading into it. Any suggestions would be appreciated by this sleepless renter… Thanks.
Banging occurs in steam radiators that are trapping water inside. The extra water is picked up by repidly moving steam and slammed against the other end of the radiator. Pooling of water inside the radiator can be caused by improper pitch (slant) away from the pipe that allows the water to flow down back to the boiler. Rust and dirt can collect in the bottom to create a barrier to water flowing out of the radiator. Two-pipe steam systems had steam traps at the bottom pipe of the radiator that can malfunction to resist water flow out of the radiator.
Thank you for having all of this information so accessible. The only problem is that I didn’t find any suggestions about how to remedy the situation. Would you recommend bleeding? Or at this point does the super need to do something near the boiler end?
The banging is miniature explosions that occur when steam, (which has a lot of extra potential energy), meets a pool of water and condenses instantly releasing that energy. You could have a bad trap that is retaining the water in the radiator, or one that is letting the steam leak through and contact the water in the return system. In either case, the building maintenance should be able to fix it by repairing/replacing the return trap.