Removing and replacing cast iron water radiators

Bumble

How risky is it?. What do I do to heat the house while one of the radiators is missing? Must I drain the entire system to remove one radiator.

Basic stuff, but I don't know. Thanks for any advice.

Bumble

Removing and replacing cast iron WATER radiators

How risky is it?. What do I do to heat the house while one of the radiators is missing? Must I drain the entire system to remove one radiator.

Basic stuff, but I don't know. Thanks for any advice.

Ross_8

why would you want to?

Ross_8

why would you want to?

Bumble

To repair badly damaged plaster wall behind radiator.

Mike T., Swampeast MO

Very little danger as the unions are brass and tend to come apart with relative ease and very little chance of damage. The captive nut of the union stays on the radiator side, so to REMOVE pull UP with the wrench on a RIGHT-SIDE connection and DOWN on a LEFT-SIDE connection.

At a minimum you must drain the system to below the connections of the removed radiator(s). When draining you MUST air bleeds at the highest radiators. Turn the boiler OFF at the SOURCE before draining.

If you're not familiar with hydronic systems, I highly suggest that you call someone in to re-fill. Incredible number of variables when it comes to filling.

Bumble

This spells it out. Thanks. Had not occured to me that refilling would be a problem.

Mike T., Swampeast MO

When you go to reinstall the radiators, wipe the mating surfaces of the unions with a clean rag. Do not force when tightening--again they're brass and relatively soft. Better to have a weeping leak requiring tightening than overtightening and distorting the mating surfaces.

Bill Jirik,

I often use a little silicone gasket sealer (available at an auto parts store) on the mating surfaces of the unions, assmble the unions and snug up allow a day or two to cure before filling the system and you will have no leaks, plus it will still unscrew easily even after it has cured.

Bumble

Excellent warning: to risk a leak rather than strip the threads.

Your earlier advice about loosening unions - do I understand correctly that to disconnect I screw unions ONTO the threaded stems coming out each side of the radiator? Just checking that I understand.

Bumble

What do I call the little silicone gasket? Sometimes I have trouble finding the right thing in an automotive store.