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