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 air vacuum relief valve replacement
Author: leakyring (AR)

I have a Marathon water heater in a rental that just malfunctioned and flooded the house. It looked loke lime hadbuilt up and opened the valve releasing water. Can I use a plug to go back or is it aboslutely necessary to just get another valve. Water heater has a pressure relief valve which is piped to outside, but this air vacuum valve releases into the buildings' closet and everywhere else then. I was told only a plastic tank unit has to have this valve installed. But is a poor design flaw if when it opens and floods everything. Any advise, expertise is apprecciated

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 Re: air vacuum relief valve replacement
Author: bernabeu (SC)

a plastic tank MUST have a vacuum relief valve


replace said valve


replace the tank with one not requiring said valve

ps. quality plumbing is expensive, crap plumbing is MORE expensive

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 Re: air vacuum relief valve replacement
Author: packy (MA)

this is from the phoenix code..504.1 Antisiphon Devices
An approved means, such as a cold water "dip" tube with a hole at the top or a vacuum relief valve installed in the cold water supply line above the top of the heater or tank, shall be provided to prevent siphoning of any storage water heater or tank.

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 Re: air vacuum relief valve replacement
Author: bernabeu (SC)


'most' marathon as well as 'some' rheem are 'lifetime' plastic and require 'anti collapse' external vacuum breakers to prevent a MECHANICAL failure of the tank

different protection than anti siphon

as a WAG an atmospheric vacuum relief may have been installed instead of a MORE EXPENSIVE pressure vacuum breaker

atmospheric breakers fail totally when the 'duckbill' blows out, pressure breakers merely start to leak

Edited 1 times.

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