Replacing rad valves - right or wrong way

john_181

I have to replace some bad rad valves in my hot water heating system. The system is over 70 years old. Is there a right way and wrong way to change them? Is there anything I should do or look at? Also do I need to change the nipple in the rad or just change the valve and done????

All help welcome - THANKS

Jim Bennett

Well....

it all depends on how handy you are. This might be better left to a professional, but if you know your way around a set of tools you can do it.

You will need to change the valve and union nipple complete. The chance of finding a new valve that will mate with your original ones is very slim.

You will need two pipe wrenches, one on the pipe and one on the valve. When adjusting the wrenches, set them open far enough so the teeth bite, but the pipe also touches the back of the wrench. This is a "three point bite" and is less likely to crush things out of round.

Use equal pressure on both wrenches, you don't want the pipe turning below the floor.

The union nipple is another story. They are assembled with an internal wrench, but almost never come out the same way.
I cut the union nut off and remove the nipple with a pipe wrench. Works every time.

I would also caution you not to do this:
(1) After the supply house is closed
(2) In the heart of the heating season unless absolutely necessary. (remember Murphy's Law)

Good luck,

Jim