TPRV extension Pipe

Im inspecting a 2017 house and want to get everyone’s opinion on this extension pipe. When the building standard calls for to terminate not more than 6 inches above the floor. Does this look correct in the picture attached ?? (Pex and PVC pipe are not corrected together)![DSCN0848|640x480](upload://47JdnUtDSCN0854 DSCN0855 pgTASx50aR3kOM93hU6N.jpeg)

It would be better if the pex was in the dam pan.(Not much…but, better). IMO

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It’s not good enough for the discharge pipe to terminate in the pan in the installation shown because it will still be too high. The idea is to prevent scalding during a discharge event. The stand is too high off the floor and during a discharge someone standing near the tank can get a burn from the almost boiling or worse superheated water. I would recommend it terminates no higher than 6" off the floor.


It’s improper as configured.

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Where’s the pan?

you are right to question it!
It will not pass here, the rule is 6" min. from floor like you said, no fittings should be present till after it goes to the recommend 6" and they have a PVC 90 then CPVC pipe, if the TPRV opens it will blow it out.
PVC is not recommended for hot water let alone heat like what would be coming out.

And like Simon said even in the pan it’s not good, this is one of the normally 18" pedestal, that’s to high for discharge.
It could blow and reflect up from the pan right on someone.

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The pan makes no sense as they are only required for installation above a living area. If the TP valve discharges a person will be scalded trying to turn the hot water off especially when it sprays all over from hitting the water heater stand. Extend the TP discharge pipe 6” above floor and pay no attention to the useless pan. TP discharge pipe shall be make from material approved in that jurisdiction for potable water. Mileage may vary.

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Oddly all the new installations (require a pan) have the TPR elbowed over the pan lip if there’s no floor drain. Just had a water heater installed and the county plumbing inspector says that’s the way it has to be. Haven’t looked it up but we (MD) use the National Standard Plumbing Code. I’ll have to find a more recent copy of that.

Worth adding to your technical libraries.

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Thanks Chuck your right!

In the 2018 National Standard Plumbing Code:

For my application (MD installation) an apparent difference is the allowance of a high impact plastic pan under a gas water heater (which I have - (b)). The drainage section ( (b)) indicates that TPR discharge is allowed into the pan when the pan is connected to a drain. Mine is not so the TPR has two elbows to miss the drain pan.

The IPC 504.7 states, “A plastic pan shall not be installed beneath a gas-fired
water heater.” In 504.6.5 states, “Discharge to the floor, to the pan serving the water
heater or storage tank, to a waste receptor or to the outdoors.” So makes no distinction between a drain pain that has a drain and one that does not.

It does appear that the OP’s installation does not have a drain for the drip pan (probably the reason the TPR discharge misses it). The WH is electric so the plastic pan is acceptable by IPC code (most of the country).

That’s about the worst seismic strap I’ve seen on a water heater in a long time.

Why would you say that?

It serves no purpose in that application. A hot water heater pan is used to protect property under the tank. Clearly this is installed over a concrete slab most likely a garage.

It is obviously a garage. You can see the overhead door rollers bottom right of picture. Code requires a pan now, whether or not it’s helpful. Installations in my area require county inspections, so you know they’re going to add the pan.

You can’t fight city hall or win an argument with a county inspector!

My uniform plumbing code book states a pan will be installed where discharge will cause damage. In 33 years of plumbing the only place I’ve ever install the pan is over of a living area. Every state every county every city has different codes. Sometimes a state adopts the uniform plumbing code. Some states have their own codes and every city and county can improve those codes.

504.7 Required Pan

Where a storage tank-type water heater or a hot water storage tank is installed in a location where water leakage from the tank will cause damage, the tank shall be installed in a galvanized steel pan having a material thickness of not less than 0.0236 inch (0.6010 mm) (No. 24 gage), or other pans approved for such use.

That is the IPC not the National Standard Plumbing Code.

Like so many things though, " is installed in a location where water leakage from the tank will cause damage." is certainly subject to interpretation. So how much of that 50 gallon tank will that little pan hold anyway?
Point being if the pan is not connected to a drain (which mine and many others aren’t) it’s fairly useless anyway.

That’s the problem with codes. I remember in the early 90s Illinois tried to get away from words like may. The next revision of the codebook eliminated those words and use words like will and shall. When water heaters fail the drip pan will be sufficient to collect the water and allow an occupant to see the water heater is leaking. Even a leaking temperature pressure relief valve generally is a slow discharge. A catastrophic failure with the temperature pressure relief valve operating, I doubt that pan will safely contain the volume of water discharging from the pipe. I’ve never seen a full on TPR valve discharge in a fully opened position. I’ve seen many many leaky water heater‘s and TPR valve that drip as the seal and poor spring condition leak.

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.

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