Clarification on Water Heater T&P Relief Discharge Code in Calif.

[tshannon]

Hi everyone,

Thanks for all the knowledge on this forum! I love browsing and learning here.

I am getting ready to replace my old gas water heater with a new heat pump water heater. The water heater is in the garage with no floor drain and with no access to an exterior wall. Therefore, I'm thinking of discharging the temperature & pressure relief valve into the adjoining laundry room's utility sink. However, I am stuck on the wording of California Plumbing Code 608.5(3), quoted below:

"Discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of the building with the end of the pipe not exceeding 2 feet (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards."
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So draining via an air gap into the utility sink basin seems to fall into the category of discharging "into the drainage system". What I can't figure out is if the end of the pipe must be 6" - 24" off the ground only when it's being discharged outdoors or if the height off the ground requirement also applies to pipes discharging into the drainage system. The rim of the sink is 33" off the ground, so I'd be looking at a discharge height of at least 34".

I would love to speak to my local inspector about this but COVID has made it very difficult to get in touch with them :/

Thank you!

 

[WorthFlorida]

....the wording of California Plumbing Code 608.5(3), quoted below:

"Discharge pipe shall discharge independently by gravity through an air gap into the drainage system or outside of the building with the end of the pipe not exceeding 2 feet (610 mm) and not less than 6 inches (152 mm) above the ground and pointing downwards." .​

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The height is only applicable when discharging outside. Where is the gas water heater and how is the T&P discharge pipe setup?

 

[Sponsor]

 

[tshannon]

Ok, I originally thought the height requirement only applied to outdoor discharges, but figured it could be read the other way too, where the height applies to both indoor and outdoor discharge setups. Thanks.

Currently, the old gas water heater is in a closet (with full louvered door) in the garage and the t&p discharge pipe drains into the pan. The pan does not drain anywhere. The code we follow here explicitly forbids the t&p from discharging into the pan in California Plumbing Code 608.5(7) so I know that's gotta be fixed.