Re: Draining water-logged expansion tank - need some air!
Posted by Greg C. on October 05, 19100 at 18:44:25:
In response to Re: Draining water-logged expansion tank - need some air!
A few years ago I made up a fitting for the very same purpose...I'm not only draining mine but several friends as well.
Take a 1/2" or 3/4" T fitting, put a female garden hose adaptor in one end, a drain valve in the other and a schrader valve (tire fill air stem) in the middle of the T.
When you screw this on to the drain valve for the tank, close the stop to the furnace and open the normal drain valve to the tank; put a shot of air into the tank (don't exceed 30 psi) and then open the drain valve on your T. The air you injected will rise to the top and push the water out of the tank, no more glug-glug.

Hope this helps,


: Hello,

: I have a 15 gallong expansion tank that I need to drain. The problem I having is, when I close the stop/waste
: valve between the tank and boiler and open the tank drain valve no water comes out. It seem that there is not
: enough air in the tank to let it drain. I looked but didn't see any kind of air value on the tank to let in some air.

: Any suggestions what I can do? When I open the stop/waste valve and the tank drain valve water will drain out
: but now I'm also draining water from the entire system.

: Thanks,
: Tom

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