Water heater TPR drain when in attic?

My question is… when inspecting a hot water tank in a attic where should the TPR drain pipe lead to; since it’s not supposed to lead to the drip pan?

It should lead to and terminate to the exterior of the house with no more than four 90 degree angles and always in gravity flow slope.

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If the water heater is installed in the attic it should be installed in a pan. The TPRV discharge piping may discharge into the pan. It may also discharge to the outside. Now you will have two pipes doing the work if one pipe. The pan should discharge to the exterior or a P-trap that ties into the sanitary sewer. Codes vary by region so contact a local plumbing contractor.

Says who, are you in UPC? Why can’t the discharge pipe terminate into the pan? You cannot discharge into the water heater pan in UPC territory. It’s best not to just not blanket a requirements as every jurisdiction is different. Most follow IPC.

In the interNachi training material is says the TPR is not allowed to drain in to the water heater drip pan.

It’s clearly wrong Matthew. The majority of jurisdictions follow the international plumbing code where this is allowed. It is not allowed in the uniform plumbing code jurisdiction. As a new inspector you will need to understand some of the basic regulations in your area. This is one of the discussions that has brought up quite frequently and debated. When you start inspecting if you ever see something that looks unusual just note in your report that it may require further evaluation by a licensed contractor of that specific craft.


According to present day requirements, water heaters should have a pressure relief valve and drain line which flows by gravity to the exterior, or downward to within 6 inches of the structure floor. The size of the drain line should match the outlet size of the relief valve, and an auxiliary pan with a 1" drain line, which drains to the exterior is required underneath when the unit is installed at or above the level of the living area.

Simple enough huh?


See item 5

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You would think but there are actually four options.

It has worked for me for over several millenniums .

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Jesus your old.

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You haven’t been drinking again while posting ?
Just jokin’ with you Brother… Yep!

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Mama gets home in 20 minutes I suppose the first tequila will begin to flow at that time.

I knew Thomas Edison! And Marconi… Not!

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Tanqueray and tonic.

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Tequila on the rocks. Sometimes I’ll throw in a dash of white claw for a little extra flavor. But not much I don’t want that crap diluting my experience.

Why not?
I like you a lot Inspector Martin… Yes! :sunglasses:

I like you too Roy. I think we would get along just fine. Yup.

I’m sure we would Brother… You make me laugh!
And that is important… Yep!

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