Water Expansion Tank - What Pressure to Set It To?


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Old 01-20-12, 11:33 AM
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Water Expansion Tank - What Pressure to Set It To?

About an hour after taking two showers, when I turn on a hot water tap there is a burst of water for about a second and then the pressure drops to normal. Didn't used to be that way, so I suspected the expansion tank (Water Worker A 101 I believe).

I measured the pressure in the tank with all water taps closed and the heater not heating and found it to be 90 psi. The house water input pressure is about 70 psi. The water heater is 40 gallon. Is 90 psi a bit high for the expansion tank and if so, what should it be and under what conditions do I set it?
 
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Old 01-20-12, 11:57 AM
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The expansion tank pressure should be set what the pressure is in the home. You state 70psi. To adjust the air the water line must be relieved of all pressure. Shut off the main and open a faucet. Once there is 0 psi on the system you can adjust the tank pressure.

Other then that check to see if you have a pressure reducing valve at the water main. If so then check the house pressure at various times of the day and post the results back here.

Pressures should remain pretty constant. If not then faulty prv or exp tank.

Mike NJ
 
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Old 01-20-12, 01:19 PM
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Thanks for the info, Mike! That answers my questions.
 
 

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