anti backflow valve

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1

Originally Posted By: chorne
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Hi all,


Is the installation of an anti backflow valve on a water heater


code?


I rarely see them here in NH

Carla

2

Originally Posted By: John Clayton
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In my area (IPC), Antisiphon devices are required on water heaters and storage tanks. The dip tube on a standard water heater serves this purpose as long as it has a small hole in the tube near the top. However if there is no hole on the side of the dip tube and for side / bottom feed tanks and storage water heaters the installation of a vacuum relief valve on the cold water line above the height of the tank is required.

3

Originally Posted By: chorne
This post was automatically imported from our archived forum.


Thanks John,


Is the vacc. relief valve code?

friends in Mass. tell me that it is

Carla

4

Originally Posted By: John Clayton
This post was automatically imported from our archived forum.


Are you asking if the VRV is mandatory on all water heaters or asking if it meets the requirements as an antisiphon device…


Anyway, you are in NH which is using the International Codes if i'm not mistaken. Your friends in MA are using their own code which I believe is an amended version of the Uniform Code.

The IPC states
"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."

"Bottom fed water heaters and bottom fed tanks connected to water heaters shall have a vacuum relief valve installed. The vacuum relief valve shall comply with ANSI Z21.22"


I would think it should be assumed that all standard top feed water heaters have the proper dip tubes installed with the small hole near the top to prevent siphoning so they would not need an additional VRV, but it would be mandatory to install a VRV on bottom feed water heaters as per the IPC. However, every state city and individual code inspector enforce different codes or amended codes.

5

Originally Posted By: chorne
This post was automatically imported from our archived forum.


Thanks John