When checking air pressure of an already installed expansion tank, you first have to shut off the water main valve so that there is no water pressure coming in; then you open some faucets so that you relieve the system’s built up pressure. After that you can get a more accurate measure of the air pressure in the expansion tank, and fill it to the appropriate pressure. And you do not have to drain the water heater tank to check the air pressure.
Yes, I was also wondering that. Also, if you fill the tank with air that matches your water supply pressure, no water would normally enter the tank, right? So the expansion tank would be 100% air, not half filled with water as he said at the beginning of the video. I think the factory pressure of 40 psi is adequate if your supply pressure is 70 psi. Some water will enter the tank until the pressure equalizes, that’s how it was designed to work.
@@heinzotto1194 Your later points are incorrect. As the water expands, it enters the expansion tank and compresses the air or bladder inside. When the hot water is used, and the temperature decreases, the water inside the expansion tank is pushed back into the main water supply. remember to check the pressure of expansion tank often. It can loose pressure just like your car tires do, more so in fall, when outside temps fluctuate.
A thermal expansion tank is only necessary if the water heater is part of a closed system. A closed system is created when there is a check valve in the incoming water supply that prevents the expansion of heated water from flowing back into the water main.Jul 26, 2019
RUSTY,my street pressure is 120 psi,but has gone as high as 130psi,so I installed a PRV, PRESSURE REDUCING VALVE,set to 65 psi,all has been as of 1976,when I moved in., 🇺🇸🇺🇸🇺🇸🇺🇸
The tank should be mounted such that the process connection is at the top, so the air bubbles can rise up and out of the water side of the tank. If the tank is on its side, air can get stuck inside and cause corrosion at the steel tank wall.
I went to check my relief valve plumbing, it seems to exit outside the home. I'm a little surprised on our water pressure (located south of 44) it was approaching 75 pounds. Thanks!
The outside tap may not be the same as much of the rest of the house and subsequently the expansion tank. Depends if it's coming off a balanced supply or the main. That's why it's not a case of simply matching the tank pressure to outdoor tap pressure.
I have an inlet pressure reducing valve pre set at 12psi. Yet my boiler runs 20 psi cold and almost 25 psi hot. The expansion tank also precharged at 12 psi. My home is only one story (with basement where the boiler is) and the highest piping point is about 8 feet from the boiler. The boiler was installed with the expansion upside down, meaning valve stem points towards ceiling. The circulator was installed right before the return into the boiler. When the maintenance guys come they always say that's ok. I don't believe it. Would adding or reducing pressure from the expansion tank help the problem because there doesn't seem to be any other way to lower the pressure?
1 - Have the expansion tank installed the proper way. It must be pressurized to the match the cold static pressure. 2 - It seems like your prv/auto-fill is not functioning properly. 3 - It's not ideal to have the circ on the return, since that could introduce air in the system, but that is probably not the cause of your issue. Can you tell us where the expansion tank auto-fill is installed? 4- These expansion tanks need their pressure checked yearly. That is why I always install them with an isolation valve and a purge. Webstone makes some nice fittings for this.
My house water psi is set at 55. I set my expansion tank psi to 55. I have a dedicated bib that I keep a pressure gauge on, why would it show 90psi after the water heater completes a heating cycle if the expansion tank is supposed to keep the water psi equalized?
It will go up because of the heat of the water expanding , but up that high , you might want to check and make sure the tank is working properly and not leaking air . Shut off main water valve, drain lines to relieve pressure and THEN check pressure in tank, if you set it at 55, it should still be around that pressure , if it’s low, check and see if the valve is leaking air or the bladder might be leaking ?
We had the water pressure checked at meter and it was 100 psi. Our house is about 200 feet down hill from the meter. Should we still check it again at the house?
Still confused. It seems to me that you would need to check the tank air pressure with house water pressure behind it. If you put 70 psi in there with no water even connected then you install it and your water pressure is say 69 pai, There will be NO water in the tank. Also, you should mention the underlying reason this tank is needed in the first place. It is because modern water supply require by code an anti- backflow check valve to prevent contamination of the city water by anything in your house. Without the check valve an expansion tank in not needed because the water can expand right back into the supply line.
what good is the bucket if the pipe is almost to the bottom so when it fills you basically have to dump it while taking it away, maybe cut that pipe otherwise great info
Just make sure you have an insured, bonded, licensed plumber within your state requirements to check your water supply and water pressure! Between 35 and 75 psi, you have a questionable problem!
Yes if you are going to have a plumber do it. But this is an easy check for a home owner to do once a year. Yes if you are pushing over 80psi you need to look into it I believe. Have a great day and thanks for jumping in.
When checking air pressure of an already installed expansion tank, you first have to shut off the water main valve so that there is no water pressure coming in; then you open some faucets so that you relieve the system’s built up pressure. After that you can get a more accurate measure of the air pressure in the expansion tank, and fill it to the appropriate pressure.
And you do not have to drain the water heater tank to check the air pressure.
Thanks
Thank you you answered the question in my mind 😂
Yes, I was also wondering that. Also, if you fill the tank with air that matches your water supply pressure, no water would normally enter the tank, right? So the expansion tank would be 100% air, not half filled with water as he said at the beginning of the video. I think the factory pressure of 40 psi is adequate if your supply pressure is 70 psi. Some water will enter the tank until the pressure equalizes, that’s how it was designed to work.
@@heinzotto1194 Your later points are incorrect. As the water expands, it enters the expansion tank and compresses the air or bladder inside. When the hot water is used, and the temperature decreases, the water inside the expansion tank is pushed back into the main water supply.
remember to check the pressure of expansion tank often. It can loose pressure just like your car tires do, more so in fall, when outside temps fluctuate.
A thermal expansion tank is only necessary if the water heater is part of a closed system. A closed system is created when there is a check valve in the incoming water supply that prevents the expansion of heated water from flowing back into the water main.Jul 26, 2019
Incorrect
@@benmattson5649 Sorry but this is correct. An expansion tank is needed because of the check valve,
Good job Rusty . . . Dr. Roy Hinkley would be proud.
RUSTY,my street pressure is 120 psi,but has gone as high as 130psi,so I installed a PRV, PRESSURE REDUCING VALVE,set to 65 psi,all has been as of 1976,when I moved in., 🇺🇸🇺🇸🇺🇸🇺🇸
It can get high and when it does it can also damage things. Subscribe for new Videos: bit.ly/3aToJ3H
The tank should be mounted such that the process connection is at the top, so the air bubbles can rise up and out of the water side of the tank. If the tank is on its side, air can get stuck inside and cause corrosion at the steel tank wall.
funny enough my tank is corroded a the top from water escaping and sitting then slowly dripping down
Thank you Rusty you are awesome with a lot of helpful information
I went to check my relief valve plumbing, it seems to exit outside the home.
I'm a little surprised on our water pressure (located south of 44) it was approaching 75 pounds.
Thanks!
The outside tap may not be the same as much of the rest of the house and subsequently the expansion tank. Depends if it's coming off a balanced supply or the main. That's why it's not a case of simply matching the tank pressure to outdoor tap pressure.
I have an inlet pressure reducing valve pre set at 12psi. Yet my boiler runs 20 psi cold and almost 25 psi hot. The expansion tank also precharged at 12 psi. My home is only one story (with basement where the boiler is) and the highest piping point is about 8 feet from the boiler. The boiler was installed with the expansion upside down, meaning valve stem points towards ceiling. The circulator was installed right before the return into the boiler. When the maintenance guys come they always say that's ok. I don't believe it. Would adding or reducing pressure from the expansion tank help the problem because there doesn't seem to be any other way to lower the pressure?
1 - Have the expansion tank installed the proper way. It must be pressurized to the match the cold static pressure.
2 - It seems like your prv/auto-fill is not functioning properly.
3 - It's not ideal to have the circ on the return, since that could introduce air in the system, but that is probably not the cause of your issue. Can you tell us where the expansion tank auto-fill is installed?
4- These expansion tanks need their pressure checked yearly. That is why I always install them with an isolation valve and a purge. Webstone makes some nice fittings for this.
Thank you for sharing
Rusty! Thoughts on how to replace our boiler expansion tank that has glycol in the system, but does NOT have an isolated valve to the tank?
Thanks.
My house water psi is set at 55. I set my expansion tank psi to 55. I have a dedicated bib that I keep a pressure gauge on, why would it show 90psi after the water heater completes a heating cycle if the expansion tank is supposed to keep the water psi equalized?
It will go up because of the heat of the water expanding , but up that high , you might want to check and make sure the tank is working properly and not leaking air . Shut off main water valve, drain lines to relieve pressure and THEN check pressure in tank, if you set it at 55, it should still be around that pressure , if it’s low, check and see if the valve is leaking air or the bladder might be leaking ?
We had the water pressure checked at meter and it was 100 psi. Our house is about 200 feet down hill from the meter. Should we still check it again at the house?
thank you.
thank yuo...very simple and clear
Thanks for watching. Subscribe Button for new videos: bit.ly/3aToJ3H
My Lord.....RUSTY....don't show the innards....that's what broke up Dolly Pardon & Kenny Rodgers! lol I hope to see ya soon, friend.
Tracy
thank you for your time and video.
The expansion tank mounted wrong should be vertical, not horizontal 😮😮😮
Mine was installed and mounted horizontally ,does it matter or it’s bad idea?
I would just make sure it is braced well. That's the way mine was in my other house. Subscribe Button for new videos: bit.ly/3aToJ3H
Still confused. It seems to me that you would need to check the tank air pressure with house water pressure behind it. If you put 70 psi in there with no water even connected then you install it and your water pressure is say 69 pai, There will be NO water in the tank. Also, you should mention the underlying reason this tank is needed in the first place. It is because modern water supply require by code an anti- backflow check valve to prevent contamination of the city water by anything in your house. Without the check valve an expansion tank in not needed because the water can expand right back into the supply line.
What if you test the tank valve and no air or water comes out?
There is a leak someplace. Subscribe Button for new videos: bit.ly/3aToJ3H
what good is the bucket if the pipe is almost to the bottom so when it fills you basically have to dump it while taking it away, maybe cut that pipe otherwise great info
Smart people use a cup to empty the bucket 😮
Just make sure you have an insured, bonded, licensed plumber within your state requirements to check your water supply and water pressure! Between 35 and 75 psi, you have a questionable problem!
Yes if you are going to have a plumber do it. But this is an easy check for a home owner to do once a year. Yes if you are pushing over 80psi you need to look into it I believe. Have a great day and thanks for jumping in.
Nope. We don't have one of those expansion tanks on our water heater. And no it's not a tankless system. We have 3 levels and 5 bathrooms.
It was not always code, but it should be installed with one unless you don't care if the PRV leaks.
If you don't have a backflow check valve, then you don't
t need an expansion tank.