tapping a 2nd vent in radiator

alanm

Has anyone ever done this- tapping another hole in a radiator (steam heat) to help release more air- so you have to vents for one radiator.

Does it work? Should it be done? Any problems in doing this?

Thanks.

Fred Harwood

Two vents

Yes, installing a second radiator vent has been and can be done. However, are you sure you need to? Describe your system and how it's steam mains are vented. You instead may need better mains venting.
If you must add a vent to a radiator, drill and tap a 1/8 NPT thread a few inches higher on the rad end than the existing vent. You also can add a vent to the side of a runout fitting, but as a last resort.

Dave DeFord

Many radiators have the second..

hole already tapped and plugged. At least one of mine has a second hole about half way down the radiator under the currently-used top tapping that is simply plugged with an 1/8 pipe plug. It looks like a screw head in the end of the radiator. However getting the plug out could be a problem as most radiators aren't exactly new. Still it would probably be less risky that trying to drill a new hole.

Mike T., Swampeast MO

Maybe I'm lucky

But I've drilled/tapped a number of formerly steam rads for an air vent in a water system. Nothing but a hand drill, simple tap and cutting oil. Never had a problem. BUT, I've tried (unsucessfully) to remove those plugs...

Dave DeFord

Maybe that's the better way to go...

I can see those plugs being real difficult to remove after a few decades - especially if they've been painted a few times.

Joel_8

tapping a new vent

Please don't even try to get out an old plug unless you have enough meat to grab it with a pair of Vise-Grips. Even the vise grips won't work unless you have a lot of heat on it. It is almost always easier and safer to drill a new hole.