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How to tell if water heater expansion tank is bad

Mark EathertonMark Eatherton Member Posts: 1,160
for the memories:-) (It's supposed to be a knock knock joke, OKay...) I've been hangin around Weezbo too long..:) Just kiddin' Weezer:-) Want some coffee? My office managers hubby travels internationally as a PV solar salesman for cell phone communications, and he stopped in Somalia and brought back a suit case (maximum allowed) of this stuff that will cause your hair to stand on end and try to jump OFF of your head. And that's just from the SMELL. You drink this stuff, and there's smoke comming out of your ears and nose... Talk about ENERGY drink...

Mr Lockard forgot to tell you to expect this tank to possibly be extremely heavy, and I've almost had the schrader valve try and make a hole right through my hand because I wasn't prepared for a water logged expansion tank to come lose. Now THAT will leave a mark on you, I'm tellin' you:-)

Good luck and come back and let us know hopw you made out.



  • DaveDave Member Posts: 13

    I had the gas company come to service the boiler. He tapped the expansion tank to the boiler and said that was fine, tapped the expansion tank to the hot water heater and said it was bad because it didn't "ping" like the other one when he hit it. How can I tell for sure if this is bad? And if so does it need to be replaced or can air be reintroduced into it? The tank is 6 years old.
  • jim lockardjim lockard Member Posts: 1,059

    let me try to explain. The expansion (X) tank on your boiler is set for your boiler pressure somewhere between 12 to 18 PSI. If the tank is bad and the water has nowhere to expand it will overflow the pressure relief valve and the floor will be wet.
    As for the water heater that X tank is set at 40 psi or so from the factory it needs to be set to your local water pressure. The correct way to set up the X tank is to determine your water pressure (water pressure gauge)you can check it at the water heater drain or a hose bib on your home.(with all water use off) read the pressure at night or midday is the best. Valve off the water to your X tank and remove it, on the top you will see a air valve check the pressure with a tire gauge. You will need to adjust the pressure to you local water pressure plus 5 psi you can use a bicycle tire pump to accomplish this. Should your X tank fail to hold pressure then it must be replaced. Best Wishes J.Lockard
  • jim lockardjim lockard Member Posts: 1,059

    ME for catching the details. To much coffee
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