I am on a well system, do I require a hot water expansion tank on top of my well bladder tank?

I assume that by "on top" you mean "in addition to". The answer is no, not unless you have a check valve between the water heater and the well tank.

I assume that by "on top" you mean "in addition to". The answer is no, not unless you have a check valve between the water heater and the well tank.

Hmmm that is what I thought however been told otherwise and can not understand the requirement. My well pump is set to 40 low 60 high and the well bladder is set to 32 psi. My pressure release valve, gauge and master switch ( the electronic device which controls the pressure) was replaced in January 2009, I noticed a drip of water at the pressure release valve, it seems to go away and then I noticed a drip at the hot water heater pressure release pipe which was a little more then a little drip. My shower has started dripping in the middle of the night I am guessing when water heater kicks in. I called the well people and informed them of this and they said it was due to the lack of a hot water expansion tank.. I scratch my head as in all the research this hot water expansion unit is set to max water pressure which in this case would be 60. In my mind I am adding a unit and not creating any weak points for this therminal expansion as my well bladder is set to 32? I am so confused

What appears to be confusing you is not understanding what things do and what there purpose is.

First your well tank. If you well switch is set to cut on at 40 lb and off a 60 lbs your tank pressure, when the tank is empty of water should be set at 38 lbs. That way you pump comes on just before you run out of water. Turn the pump off. Open a faucet and drain the tank of all water. Then set the air pressure to 38 lbs. and turn the pump back on.

The T&P valve (temperature and pressure) on you water heater is an emergency release valve. It is set to release water should either the temperature or the pressures gets too high. Because they sit inactive for long periods, corrosion or sediment can build up. Once opened this corrosion or sediment can cause them to not seal properly. For that reason you do not mess with them. If you do, you may have to replace it. Some times after a period the spring may get weak and they begin dripping. If so it is time to replace.

When the water in the water heater is heated it expands and pressure increases. This pressure cannot be released through the hot water side because the faucets are closed. The increased pressure is released back up the cold water input line unless the a check valve has been installed.

If a check valve or PRV valve (Pressure Regulating Valve) is installed the pressure cannot be released back up the cold water line. That's when you need the thermal expansion tank. It is installed between the water heater and the check valve to absorb the water and pressure out of the water heater caused by heating the water.

The thermal expansion is not related to the well pressure tank.

A leaking T&P valve indicates time to replace.

To have shower valve start dripping in the middle of the night might be related to a small increase in pressure but primarily indicated a need to replace the cartridge.

What appears to be confusing you is not understanding what things do and what there purpose is.

First your well tank. If you well switch is set to cut on at 40 lb and off a 60 lbs your tank pressure, when the tank is empty of water should be set at 38 lbs. That way you pump comes on just before you run out of water. Turn the pump off. Open a faucet and drain the tank of all water. Then set the air pressure to 38 lbs. and turn the pump back on.

The T&P valve (temperature and pressure) on you water heater is an emergency release valve. It is set to release water should either the temperature or the pressures gets too high. Because they sit inactive for long periods of time, corrosion or sediment can build up. Once opened this corrosion or sediment can cause them to not seal properly. For that reason you do not mess with them. If you do, you may have to replace it. Some times after a period of time the spring may get weak and they begin dripping. If so it is time to replace.

When the water in the water heater is heated it expands and pressure increases. This pressure cannot be released through the hot water side because the faucets are closed. The increased pressure is released back up the cold water input line unless the a check valve has been installed.

If a check valve or PRV valve (Pressure Regulating Valve) is installed the pressure cannot be released back up the cold water line. That's when you need the thermal expansion tank. It is installed between the water heater and the check valve to absorb the water and pressure out of the water heater caused by heating the water.

The thermal expansion is not related to the well pressure tank.

A leaking T&P valve indicates time to replace.

To have shower valve start dripping in the middle of the night might be related to a small increase in pressure but primarily indicated a need to replace the cartridge.

You are correct, I may not understand these items and is why I had a Plumber replace the items and they set the settings not I. My Water heater 50 gallons was also replaced in January 2009 and a entire house water filter also installed the leaking shower is in a bathroom which was a total gut job in March 2009. I don't have a check valve and my thoughts were any thermal expansion taking place would migrate to the well bladder and it could and would handle and thermal expansion pressure.. So since the pressure release valve on well pumb, hot water heater and middle of the night show drip are in somewhat new items I am assuming that is why the well people want to add this HOT WATER EXPANSON tank. Again makes no sense since pressure will move to weakest point which should be the Well bladder however this does not seem to be happening.

Water filter installation may have or require a check valve some where, but I don't know.

Water filter installation may require a check valve some where, but I don't know.

No check valves in water filter either, having indicated these drippings in items aprox 1 year or less of age would you also think thermal pressure issue?

Water filter installation may have or require a check valve some where, but I don't know.

I went out today and picked up a gauge and attached it to the well pressure drain and here is the findings.



When laying on the ground I get a better view of existing gauge .

Existing gauge is reporting at pump start 38 PSI when pump stops 58 PSI.

New gauge is reporting at pump start 35 PSi when pump stops 55 PSI.

After first cycle of pump the shower running for 3 minutes the pump kicks in for 30 seconds. And that cycles remains the same as do the pressures above. Verified well pressure tank when empty of water is at 32 psi.

I'd be interested in getting a pressure reading inside the house. That would address your concerns of leaking TP valves/shower.

How big is you well tank. You pump is short cycling. The only reason for short cycling is a water logged tank (tank completely filled with water). That should not be occurring, seeing as how you just drained it. It should never occur with a bladder tank unless you ruptured bladder.

If you bladder is ruptured and you completely drain and pressurized it the pump should not short cycle until the air in the tank is absorbed by the water.

Might want to drain again making absolutely sure that all of the water is out of the tank. Tap the side of the tank with a wrench. You can hear the difference if there is water in the tank.

The good news is that the leaking of the T&P valve could be related. If the well tank is water logged (completely fill with water) there is no where for the heated and expanded water in the heater to go. Therefore the T&P valve releases some pressure.

Turn pump off, open drain valve and faucet and drain tank. When all water is drained from tank the tank should still hold the air pressure. If you have a leaking bladder you should lose the air pressure out the drain valve and faucet. Give it some time. If you have a leaking bladder you may get air out the faucet or you may get a slow stream of water.
If the bladder has a leak, the pressure will eventually drop to zero.