How to Replace a Steam Radiator
Ask This Old House plumbing and heating expert Richard Trethewey replaces a small radiator with one that’s the correct size
- Switch off the steam boiler to prevent risk of scalding.
- Loosen the nut holding the radiator. Make sure the wrench is biting the nut in three different corners to prevent the nut from deforming.
- Carefully remove the old radiator.
- (Optional): To replace the hand valve, use one wrench to bite the pipe and one wrench to bite the valve. Move in opposite directions to loosen. This step may require a pipe for persuasion.
- (Optional): To replace the spud, insert the spud wrench to loosen, then remove.
- Make all the necessary connections with the wrench: floor to hand valve, hand valve to spud. Apply the pipe dope and the wicking to each thread to ensure a secure connection. The hand valve should be parallel to the floor in order to fit back into the radiator.
- Carefully fit the new radiator into place and connect it with pipe dope and the wrench.
- Open the hand valve and turn the boiler back on.
Richard used an existing radiator left over in the homeowner’s house, but a replacement radiator could be bought at plumbing supply stores or salvage yards.
The other tools for this project, including the hand valve, pipe wrenches, and a spud wrench can be purchased from a plumbing supply store.