Water pressure and expansion tank

Old 10-19-18, 07:39 AM
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Water pressure and expansion tank

Does the house water pressure and the pressure in the expansion tank have to be the same? I know if the water pressure is higher then the tank should be too but if the tank is high say 75 does the water pressure have to be that or can it be lower?
Old 10-19-18, 07:57 AM
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The instructions for the one I recently installed said to set the air pressure to be the same as the water pressure but no more than 80 psi.
Old 10-19-18, 08:11 AM
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For best performance, the expansion tank for a water heater should be preset as described above.

If the expansion tank is already installed when presetting or repressurizing is needed, shut off the main water and open a faucet upstairs before adding or letting out air.

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