TPRV Drain Line-Many bends

I have seen some improperly run drains, but not really when it comes to TPRV drains. To me, this line has too many turns. Agree? Or if not, how is it ok?

Also, it bends again to the right, run all the way down the wall to the front of the garage and outside. :smirk:

Most water heater manufacturers limit the number of 90 degree elbows in the blow off leg to 4 or less.

Looks like you’ve got 4 90 deg elbows, plus a 45 and whatever else you found outside.


James, as Nate said it has 4 - 90 degree elbows plus the one bend outside and a 45 degree elbow which is more than is allowed.

Recommend correction of the TPR discharge pipe by a qualified plumber, for enhanced safety. :smile:


lack of support at elbows.

1 Like

Thanks a bunch to all of you. I thought it was strange.

Some of those connections don’t even look glued…

This is a standard Rheem installation manual. Page 10 addresses relief valve discharge.

I can’t find a reference in the UPC mentioning number of elbows on the relief drain line. Can someone post if you can find the code? 608.5 addresses relief valve guidelines.

There is no code for limit on number of elbows… the limit comes from the appliance or the valve’s installation requirements. Some say 2 elbows and no more than 15 feet of developed length, some say 4 elbows and no more than 30 feet. So you have to be very carefully if and how you call it out.


Simon you are correct. I was just throwing out the information to see if it stuck to anyone’s wall.

1 Like

And here a Watts tag says more than 4 elbows will cause a reduction in discharge capacity! WTF! It doesn’t say you cannot use more than 4 elbows. I would call out any defect that differs from the tag such as “discharge may be reduced if valve is operated”. Of course the tag may not be present during all inspections.

It seems to be according to manufacturer instructions. However, no part of the discharge pipe should be pointed upward in any of its course (to prevent the chance of a blockage). So even if the elbows are okay, this one would still be a concern, would it not?

It’s hard to see from the angle of the photograph if that last 3” horizontal leg of the discharge pipe is back graded. The pipe should be strapped between those elbows and the exit of the wall for sure.

1 Like

It is a bit of an illusion! :grinning:

You may be right the longer I look at it :face_with_monocle:

Haha! Yeah, it depends how long you stare at it! :grinning:

1 Like

All those elbows are hypnotizing me🤪

1 Like

Keep it simple folks, it is definitely atypical discharge configuration, call it out for review and correction, if needed, by an expert. CYA! It should not disappear into a wall, plus all those elbows.


All that piping and elbows, most costly discharge pipe I’ve seen! :grin:

The T&P discharge tube also shouldn’t leave the room it is in unless first discharged through an air gap. Otherwise some could cap the “leaking pipe” on the other side. Bombdiggity.


In Illinois, the occupant is suppose to have the opportunity to notice if the valve is activating, that is the reasoning for the air gap in the same room. There are about a dozen different restrictions on how to terminate the TPR valve extension. To my knowledge, plastic tubing is also not allowed in IL.