Hot Water Heater Expansion Tank Full

[Stephanie Dowling]

My expansion tank is completely full of water and there is no remaining pressure. It's too heavy to attempt to remove on my own. 2 Questions

1. Can I drill a 1/4" hole into the expansion tank and allow it to drain before attempting to disconnect and replace with a new one?
2. While the expansion tank is draining, can I still use hot water or should I completely turn off the water to the water heater?

Thank you

 

[Reach4]

1. Can I drill a 1/4" hole into the expansion tank and allow it to drain before attempting to disconnect and replace with a new one?
2. While the expansion tank is draining, can I still use hot water or should I completely turn off the water to the water heater?

Do you have a valve that lets you isolate the tank from your water? Most people don't have one.

1. The water will have to be blocked from entering the tank. So if that, yes. However you will probably have to drill more than one. If you put air in with a pump, that can help force water out.

2. If you have that isolation valve, you can dribble water from any faucet while there is no working tank and the WH is on. That will keep pressure down.

 

[Sponsor]

 

[Bannerman]

There should be a Schrader air fitting on the opposite end from the water connection. That fitting is similar to the fitting for a tire as it will allow a bicycle tire pump or air compressor to be used to add air to the tank. When adding air, open a cold water faucet to drain the water that will be pushed out from the tank.

If the diaphragm in the tank has not ruptured, the air should remain within the tank long term, but should be checked at least yearly. The air pressure should be checked and adjusted with the main water supply valve closed and a faucet remaining open.

 

[Stephanie Dowling]

Do you have a valve that lets you isolate the tank from your water? Most people don't have one.

1. The water will have to be blocked from entering the tank. So if that, yes. However you will probably have to drill more than one. If you put air in with a pump, that can help force water out.

2. If you have that isolation valve, you can dribble water from any faucet while there is no working tank and the WH is on. That will keep pressure down.

There should be a Schrader air fitting on the opposite end from the water connection. That fitting is similar to the fitting for a tire as it will allow a bicycle tire pump or air compressor to be used to add air to the tank. When adding air, open a cold water faucet to drain the water that will be pushed out from the tank.

If the diaphragm in the tank has not ruptured, the air should remain within the tank long term, but should be checked at least yearly. The air pressure should be checked and adjusted with the main water supply closed and a faucet remaining open.

 

[Stephanie Dowling]

When you state "valve that lets you isolate the tank from your water" are you referring to the cold water valve located on the pipe that is connected to the expansion tank?
Currently, my upstairs shower head is dripping water.

 

[Bannerman]

Schrader air fitting will be on the opposite end from the tank's water connection.

An isolation valve would be in the feed line going to the expansion tank. A valve would allow the tank to be removed without needing to shut off the home's main supply valve. There is no isolation valve for your expansion tank.

 

[Stephanie Dowling]

There should be a Schrader air fitting on the opposite end from the water connection. That fitting is similar to the fitting for a tire as it will allow a bicycle tire pump or air compressor to be used to add air to the tank. When adding air, open a cold water faucet to drain the water that will be pushed out from the tank.

If the diaphragm in the tank has not ruptured, the air should remain within the tank long term, but should be checked at least yearly. The air pressure should be checked and adjusted with the main water supply valve closed and a faucet remaining open.

Yes, there is a Schrader air fitting on the end of the expansion tank and right now there is no pressure. The expansion tank is completely full of water. So, if I begin adding pressure back into the expansion tank, that will force the water out of the expansion tank .

 

[Stephanie Dowling]

Schrader air fitting will be on the opposite end from the tank's water connection.

An isolation valve would be in the feed line going to the expansion tank. A valve would allow the tank to be removed without needing to shut off the home's main supply valve. There is no isolation valve for your expansion tank.

Okay, I don't have an isolation valve...only the valve to turn off the cold water going into the hot water heater. (see picture)

 

[Bannerman]

that will force the water out of the expansion tank .

Yes, adding air should push the water out. Because water cannot be compressed, it will need someplace to go to so by opening a faucet, the water will have a place to go.

 

[Stephanie Dowling]

Yes, adding air should push the water out. Because water cannot be compressed, it will need someplace to go to so by opening a faucet, the water will have a place to go.

Yes, adding air should push the water out. Because water cannot be compressed, it will need someplace to go to so by opening a faucet, the water will have a place to go.

Perfect! Now once I've added air, and forced the water out, I should be able to disconnect the expansion tank and replace with a new one, correct?

 

[Bannerman]

It is likely the internal rubber diaphragm is damaged so the tank will require replacement, but that is not yet assured. Perhaps once the water is pushed out, the air added will continue to remain trapped in the tank as it was designed to do.

Because it is not equipped with an isolation valve, the water for the entire house will need to be shut off to remove the tank.

If you are planning for that tank or a replacement to be installed and connected as it currently is, suggest adding a length of metal strap around the tank to support the weight from above instead of all of the weight being supported by the connection pipe.

 

[Stephanie Dowling]

Thank you so much for all your help and guidance! I will definitely look into adding a metal strap around the tank.

Once more question, when adding air to the expansion tank, do I need to turn off the cold water valve or water to the entire house? I don't think so but wanted to confirm

 

[Bannerman]

The main supply valve will not need to be shut off to only add some air, but a cold faucet will need to be open.

As the compressed air held captive in the tank is normally adjusted to match the usual water supply pressure, to obtain an accurate air pressure gauge reading, the water supply would need to be shut off and the water pressure reduced to 0 psi so water will not be pushing against the air in the tank which would interfere with the air pressure reading.

 

[Stephanie Dowling]

Thank you so much! I've learned a lot during our conversation. May I reach out again should I have any more questions

 

[Stephanie Dowling]

Okay, I'm back....tried adding pressure to the Expansion tank and that didn't work, so I would imagine the diaphragm is damaged. Next step is to drill 2 holes into the expansion tank to drain the water so that I can remove and replace.

Question: Can I still use my hot water heater while the older expansion tank is draining of excessive water?

 

[Bannerman]

Can I still use my hot water heater while the older expansion tank is draining of excessive water

As there is no valve for the tank to isolate the tank from the plumbing system, you will need to shut off the WH supply valve above the tank connection. Unless you install an isolation valve directly on the tank supply line, the water supply to the WH will need to remain shut off until the new expansion tank is installed.

With the supply valve to the WH shut off, you will not have hot water flow to faucets.

What happened when you added air?

 

[Stephanie Dowling]

As there is no valve for the tank to isolate the tank from the plumbing system, you will need to shut off the main supply valve. Unless you install an isolation valve on the tank supply line, the home's water will need to remain shut off until the new tank is installed.

What happened when you added air?

Nothing but a few drips of water came out of the faucet. Even tried draining some water from the expansion tank through the Schrader air fitting and tried adding more pressure. Just a bunch of "gurgle" sound

 

[Bannerman]

Even tried draining some water from the expansion tank through the Schrader air fitting

Did water come out? If water came out from the Schrader fitting, that confirms the diaphragm is damaged.

The diaphragm's purpose is to separate the water chamber from the air chamber. Water in the air chamber signifies the diaphragm has a hole or is torn. As the tank is sealed, there is no repair option so the tank will need to be replaced.

 

[Stephanie Dowling]

Did water come out? If water came out from the Schrader, that confirms the diaphragm is damaged.

The diaphragm purpose is to separate the water chamber from the air chamber. Water in the air chamber signifies the diaphragm has a hole or is torn. As the tank is sealed, there is no repair option so the tank will need to be replaced.

Yes, water came out of the Schrader, so that definitely confirms the diaphragm is damaged. So, in order for me to remove the heavy expansion tank, I have to drain the water inside as it weighs too much for me to even attempt to remove; hence the reason to drill 2 1/4" holes into the expansion tank. Once empty, I should be able to remove expansion tank from pipe. (Let's hope)

 

[Bannerman]

After closing the supply valve for the WH, open a hot faucet to pressurized the hot lines.

Suggest drilling 1 hole at the bottom of the tank for water to exit, with a 2nd hole at the top of the tank to allow air to enter.