New water heaters with expansion tank, causing water meter to turn?

[Mj23]

Newbie here,

Plumber replaced two 50 gallon gas water heaters last week and added a new expansion tank.

Ever since then, the leak detection dial on my water meter has been spinning, intermittently, approximately every 15 to 20 seconds. The water meter is showing about 1 to 1.5 gallons of use per hour, even when all fixtures in the house are off.

No visible leak anywhere in the house. Also, I did a pressure drop test for over 20 minutes, which did not show any drop in pressure with the water shut off at the main.

Could the water meter dial turning intermittently simply be related to the expansion tank? Has anybody seen this before? For clarification, I have an open system, i.e. no pressure, regulating valve or backflow preventer at the main water meter.

 

[Reach4]

Does water come out of the drain for the temperature and pressure valve.? It shouldn't, but it would not hurt to check.

 

[Sponsor]

 

[Mj23]

No it does not

 

[Jeff H Young]

meter only spins if water is passing through it I suppose if pressure was inconsistant it could flow in to the house and into the x tank then when pressure dropped flow back into the city main. but when a meter spins water is moving one way or the other.
it cant keep spinning in the same direction if you arent using water

 

[Reach4]

What is the water pressure? What is the air precharge.

If there is no check valve, and your air precharge is lower than the peak water pressure, then I guess water could be passing in and out of the thermal expansion tank. One easy test is to shut off the feed to the water heater, presuming that the thermal expansion tank is after that valve. Confirm that the flow indicator does not move with that valve closed.

Also, get a garden hose thread pressure gauge. That can go onto a hose spigot, laundry tap, or the drain valve of the water heater.

 

[Jeff H Young]

What is the water pressure? What is the air precharge.

If there is no check valve, and your air precharge is lower than the peak water pressure, then I guess water could be passing in and out of the thermal expansion tank. One easy test is to shut off the feed to the water heater, presuming that the thermal expansion tank is after that valve. Confirm that the flow indicator does not move with that valve closed.

Also, get a garden hose thread pressure gauge. That can go onto a hose spigot, laundry tap, or the drain valve of the water heater.

Good idea shut off at w/h if meter still spins you know it leaks on the cold side. if it stops you might have a leak on the hot but its an easy test requires nothing

 

[Mj23]

OK. I I did a pressure drop test for 20 minutes come out with the main water shut off, and no drop in pressure. so I feel pretty confident that there is no leak.

I am going to have the plumber install a valve to the expansion tank. That way I can isolate it. if meter stops turning, I have my answer.

 

[Reach4]

If your water meter currently has no check valve, then you don't even need an expansion tank.

Do you have a water softener?

 

[Mj23]

No water softener.

I agree I probably don’t need an expansion tank.

 

[John Gayewski]

You don't need the expansion tank. Valve it off and remove it. If your forced to add a backflow device in the future or a regulator then you could add the expansion tank back to your system very easily.

 

[Mj23]

I agree. Expansion tank not needed. But just having it cause any problems? Newbie question.

 

[WorthFlorida]

I agree. Expansion tank not needed. But just having it cause any problems? Newbie question.

Call your water company and ask if back flow preventers are on the water meters. Many water utilities are adding them to minimize contamination.

This is why I had to dig up the meter. box. This is my son's home in Altamonte Springs, FL. You can see the brass back flow preventer on both meters. The other is the neighbors and the problem was a leak. The upper pipe is going to the home and you can see the pipe was not squred to the meter connection. Eventually the threaded coupling cracks at the meter from the stress The U shape was to allow the pipe to square up.

 

[Jeff H Young]

Call your water company and ask if back flow preventers are on the water meters. Many water utilities are adding them to minimize contamination.

This is why I had to dig up the meter. box. This is my son's home in Altamonte Springs, FL. You can see the brass back flow preventer on both meters. The other is the neighbors and the problem was a leak. The upper pipe is going to the home and you can see the pipe was not squred to the meter connection. Eventually the threaded coupling cracks at the meter from the stress The U shape was to allow the pipe to square up.

The one meter looks like it has a wye strainer ? just wondering I heard of check valves but havent seen them but looking at those I cant really tell just wondering if you are reasonably sure those arent strainers ?

 

[WorthFlorida]

Not sure myself but this year we added an expansion tank. I don't remember the pressures but it was well over 100 psi, maybe 120 so I assumed there is a back flow preventer. About a ten year old tank and the T&P started to weep water over night and during the day when no one was home. My son and I added an expansion tank and the weeping stopped. Could be the T&P went out of calibration.

What is a strainer in this setup. Nothing more than a filter? Neighborhood was built in the 70's

 

[Reach4]

What is a strainer in this setup. Nothing more than a filter?

Yes, a wye strainer is a course filter/screen. Course is relative.

If the orientation has the opening down, the debris is contained into the round screen when you clean the screen. With the orientation with the opening up, at least some sand would fall out I suspect.

Maybe it is not a wye strainer, but it sure has that look.

 

[WorthFlorida]

Learn something new every week on this forum.

 

[Jeff H Young]

Learn something new every week on this forum.

Me too keeps us learning strainer more like a screen than a filter is a bit more fine . the one on other meter appeared differant . but probebly just the angle Ive never seen the strainers installed there befor but itll catch bigger stuff . Evedently some meters have built in check valves havent seen them but only hear they are somewhat common.
As for the MJ23 I could understand wanting to remove the Xtank if its an open system just another thing to fail with little to no benefit . but Im still a little concerned over the spinning meter hope he verifys that issue