Home water pressure increases when water heater is used

Sep 15, 2006 6 Replies

Please don't post to Usenet in HTML. It sounds like someone installed a check valve on the cold water entry on the heater (or possibly elsewhere) without using an expansion tank or checking the pre-charge on the existing expansion tank. The bottom line... Heating water will cause expansion and if there is a check valve - it creates a closed system where pressure will build without an appropriate expansion vessel.

Bob Wheatley

Home water pressure increases when water heater is used.



Installed the following new parts.



  • water heater * pressure regulator on the main supply line * pressure gauge on the cold line in the house, reads 50 when nothing is turned on * relief valve on the hot water heater

After the hot water heater turns on the pressure in the system increases until the relief valve on the water heater starts to drip water out the drain pipe. At that time the pressure in the house increases to 120 and above.



We called Home Depot who installed the heater in my mothers home, they now refuse to call her.



The mfg., GE insists that the heater is good, and something else in the system must be faulty.



We have spoken to a master plumber and he asked other friends and they are stumped but insist that home depot should be involved.



What can cause this problem ?



Salto


"> pressure gauge on the cold line in the house, reads 50 when nothing is

"

The expansion tank comes pre-charged for a well(28psi), which assumes a pressure range of 30-50. you need to add air to the expansion tank, most guys fail to do so.

just look for your expansion tank and make sure it is properly inflated. sounds obvious . You might damage the water heater and void the warranty

Ken is a Plmming professor, say thank you

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