Water expansion tank/vacuum release help

[Jayb13]

I accidentally release some air from the vacuum release valve(black top/red circle) on the photo. When I refilled my tanks yesterday, water was coming out the side of my house. I shutoff the cold water intake until I figure out what’s going on. I did not touch the 2nd tank(right side) and that is functioning properly. Please help on what I should do next. Can I just pump air back in from the expansion tank? Or did I damage the tank by releasing some air out?

FYI- I measured the PSI on the expansion tank #1(left tank) and it’s at 40PSI. I didn’t let a lot of air out.

Thank you!

 

[LLigetfa]

When I refilled my tanks yesterday, water was coming out the side of my house.

Follow the pipes and I'm sure they will lead to the TPR and not the vacuum breaker.

What does air in the expansion tank have to do with a leaking TPR?

 

[Sponsor]

 

[LLigetfa]

FYI- I measured the PSI on the expansion tank #1(left tank) and it’s at 40PSI. I didn’t let a lot of air out.

The air pressure in the expansion tank should be the same as the static water pressure delivered. The expansion tank should only have water in it when the pressure rises above static.

 

[Reach4]

What does air in the expansion tank have to do with a leaking TPR?

When I refilled my tanks yesterday, water was coming out the side of my house. I shutoff the cold water intake until I figure out what’s going on.

Adding air could push water out of the expansion tank, raising the water pressure above 150 psi. This presumes a compressor that can push out 150 psi. This also presumes the pressure was not being monitored as air was added.

Air precharge should be measured and set while the water pressure is zero. 40 psi would be appropriate if that is the highest pre-expansion pressure. In some areas, city water pressure is often higher in the wee hours of the morning. So you could use the measured water pressure, and add a couple more psi of air to compensate.

 

[Sarg]

I'm guessing the pipes that exit as shown in your picture are piped to your pressure relief ( T&P ) valve. That means your pressure was exceeding their settings. The expansion tanks are designed to absorb this excess pressure to prevent that.... so something unusual was occurring. I believe the setting of the tank should be the same as the "normal" pressure within your system.
Here's a couple videos:

 

[LLigetfa]

If some time passed between when the HWT was refilled and energized meaning the TPR did not discharge right away, then it could be that insufficient precharge in the expansion tank allowed for heated water expansion to push the pressure above 150 PSI. That then would be expected. You need to set the precharge correctly.

 

[Bannerman]

The thermosatic / pressure relief valve for each tank, appear to be on the upper right side of each tank. I suspect the PVC pipes leading from each are directed to a floor drain or other suitable sewer/septic drain.

I think you are correct in referring to the circled valve as a vacuum breaker. It is possible that the vacuum breaker is now stuck open, but it may close again once the water heater tank has been filled and the water pressure for that tank is fully restored. If the valve does not close, it may need to be replaced if a rebuild kit for that model is not available.

 

[PlumbNuts]

I accidentally release some air from the vacuum release valve(black top/red circle) on the photo.

The part you have circled is a Vacuum Relief Valve, how did you release air from it?

When I refilled my tanks yesterday, water was coming out the side of my house.

The drains out side of your home are from the T&P valves that are on the upper side of your heaters, one of those have stuck partially open.
Turn your water back on and fill both units completely, go to a faucet and open the hot water until the tanks are full and all of the air has bled out.
If the T&P is still leaking then detrmine which one it is based on which drain the water is coming out of. Open the lever on the T&P fully open for a second or to the quickly close it. (You may have sediment in the seat that is keeping it from fully closing)
If this does not stop the leak then you will most likely need to replace the T&P valve.

Can I just pump air back in from the expansion tank? Or did I damage the tank by releasing some air out?

The thermal expansion tank has nothing to do with air in your heaters, leave this alone.

 

[Jayb13]

Thank you everyone for your replies. I refilled both tanks and added pressure to 1 of the expansion tanks that was compromised and everything is working again. Appreciate all the replies/feedbacks.

 

[PlumbNuts]

Congratulations! And thank you for letting us know that you have resolved the issue.