T/P valve drain line (barely) less than 3/4" i.d.

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#1

Originally Posted By: jgallant
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On two houses I inspected today, one from 1987, the other new construction, both had water heater temperature pressure relief valve drain lines using flexible copper tubing, where the narrow, upstream end was less than 3/4" outside diameter. This makes the inside diameter close to if not equalling 5/8". Everything I’ve read and heard says that the inside diameter of these drain lines should be 3/4" or larger.


An inspector friend of mine who's opinion I value said, yes, technically it's a violation, but that if the rest of the water heater installation looks correct then he wouldn't recommend any correction.

See attached jpeg. What's your opinion?

![](upload://FWkn2wW3YGyuVM4YUPD1DzE0Ok.jpeg)

-Jim Gallant

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-Jim Gallant
Owner, All Point Home Inspections - Poulsbo, WA www.allpointinspections.com
Co-founder, ReportHost (Web-based report writing service) www.reporthost.com

#2

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


If the TPR valve is REDUCED or restricted at all, it’s wrong. If the TPR valve is smaller or the same size as its piping, it’s okay.


Although I must admit, I've never seen flex tubing used for the relief valve. ![icon_confused.gif](upload://qv5zppiN69qCk2Y6JzaFYhrff8S.gif)

--
Jeff Pope
JPI Home Inspection Service
"At JPI, we'll help you look better"
(661) 212-0738

#3

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


It’s on 95% of the water heaters here. I write it up as being a reduction in size and in need of repair.

–
Slainte!


Patrick Dacey
swi@satx.rr.com
TREC # 6636
www.southwestinspections.com
#4

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


They can be less than 3/4", if the T&P valve opening is.


Many electric water heaters (most of them) really only require a 1/2" discharge valve, so a 1/2" line would work. Except that they come with a 3/4" discharge valve, and the opening cannot be reduced in size.

That is the problem. The drain line is reduced in size.

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Jerry Peck
South Florida

#5

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


I have at least one jurisdiction which is now allowing flex pipe on the TPR drain line.


![icon_twisted.gif](upload://xjO326gspdTNE5QS3UTl0a0Rtvy.gif)

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Home inspections. . . .
One home at a time.