Expansion Tank

Can someone advise me if our expansion tank is set properly?

I ask b/c we took a walk this weekend and noticed in a neighbors garage that he had what looked like the same exact tank but positioned horizontally. The reason this is curious to us is that the City still thinks our black spec issue is coming from the expansion tank (which was replaced a year ago). They thought that perhaps it wasn't installed properly when they looked at it back in Jan. We had a plumber come by and said it was fine. Now, I'm wondering if it really is now that we've seen our neighbors.

The City asked us to tap on the expansion tank at the top and that it should sound hollow which is normal. If it doesn't then it's probably that. All I hear is a clinging sound when we hit it with a spoon. Can't tell about the hollowness.

Other than taking the thing off is there another way to test this?

Also, we emptied our water heater 2 weekends ago and it ran clear until this weekend (black specs back). If it is in fact the expansion tank can it take that long to fill back up in the tank?

The tank is installed just fine. The manufacture says it can be installed the way you have it or horizontally.

Thank you! If we have a bad expansion tank, would you know what could be causing it to go bad? Like I said, it's only a year old.

If the city water is chlorinated it will eat away at the rubber bladder in the tank. What brand expansion tank do you have in there? I have always had good luck with the Amtrol. Just like anything in life you get what you pay for. Some cheaper tanks will degrade a lot faster. The Amtrol Therm-X-Trol tanks have a 5 year warranty.

When you rap your knuckles on the tank a dull thud would indicate the tank was full of water. A more or less tinny clink would indicate empty. If you're still uncertain, turn the incoming water supply and the cold water intake to the water heat off. You can then remove the tank by unscrewing it. Be very careful doing that because if it is full of water, it will weight in excess of 50 pounds. My guess is the black specks are flakes from the rubber bladder inside the tank.

Gary Swart said:

When you rap your knuckles on the tank a dull thud would indicate the tank was full of water. A more or less tinny clink would indicate empty. If you're still uncertain, turn the incoming water supply and the cold water intake to the water heat off. You can then remove the tank by unscrewing it. Be very careful doing that because if it is full of water, it will weight in excess of 50 pounds. My guess is the black specks are flakes from the rubber bladder inside the tank.

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I can not recall at this moment but do you remember a thermal expansion tank that used a metal bellow instead of the rubber bladder?

I do not. My only personal experience is with a Watts, exactly like the one you posted.

I know the plumber/whoever has told the OP that the position of the tank should not be a problem with regards to heat. I'm not so sure. If the tank works properly, hot water will back into that tank when the water heater cycles. That's what the expansion tank does, right? It is positioned close and above the tank. I can feel the heat of my water lines well up on the cold water supply side, and I don't have an expansion tank there, so mine is just contact and thermosiphon heating of the line.

The way to check this would be to feel the bottom head of the expansion tank when it is idle (no recent hot water use). Then after some major hot water use check it a few times throughout the water heater firing cycle. If the base of the expansion tank gets hot, then hot water is indeed getting into the tank. Actually, with the well insulated line on the short branch to the tank would make such a situation worse. I like insulation, but it might be counterproductive there.

Hot chlorinated water and rubber would probably lead to black specs.

Black specs could be coming from the inside of supply lines if you used flexible supply lines to the WH. Same thing on a faucet or toilet...some of those have lousy rubber, and it can flake off and create oily black specs in the tub or sink.

Well, perhaps my tapping on the expansion tank is the cause of my issues this morning. Woke up to no hot water. Noticed the pilot wasn't on and tried to ignite it and once I did that there were many flames (not so good). So, I turned it right off.

Have the plumber coming out to take a look and will have them check out the expansion tank while they are here.

As for flex hoses, it appears that we have all copper lined going into the water tank. Will discuss this with the plumber as well.

Thanks for all your input. Hopefully, I'll have some resolution and an update later today.

The Exp. tank should be charged to equal your homes water pressure...so you need to know what that is B 4 you do anything...if it was never set right the bladder could be burst...

Any plumber that does not check your water pressure and then check the charge in the Exp. tank doesn't know what he is doing....

foxhome01 said:

Well, perhaps my tapping on the expansion tank is the cause of my issues this morning. Woke up to no hot water. Noticed the pilot wasn't on and tried to ignite it and once I did that there were many flames (not so good). So, I turned it right off.

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It's a Whirlpool (see the sticky thread about those.) The pilot probably went out the day before, but you didn't notice until the hot water in the tank was depleted. The tank will easily stay hot overnight.

If it is like mine, when you relight it with a cold tank the flame might start blue, but will quickly turn yellow as condensate from the combustion gases falls onto the burner. Once the tank heats a little, the condensation stops and the burner goes back to the normal blue. The only time I've seen yellow flames is during a cold start up like this. Got my attention so I shut things down and checked before restarting. (Mine wasn't coming out the flame arrestor or anything like that, it had draft, and the CO monitor nearby was not showing anything.) Follow the lighting instructions!

A new thermocouple may or may not work on your Whirlpool. If it doesn't the gas valve is the next part to replace. The good news is that if you have to do that you will have the opportunity to look inside the tank.

Since you aren't the original owner you might have some trouble on warranty...however, there should be some way to get Lowe's to provide the parts for free without receipt. I was in the same boat and succeeded in getting them to swap parts as "defective." Take your model # and serial # from the tank with you. Your pre-home purchase paperwork might include the date of purchase of the water heater (mine did.)