What Heater Thingamajig

[Joe Funderburk, CMI]

Some sort of drain (vacuum or pressure?) at the supply line to a gas water heater. What is this and how does it work? It drains to an opening in the water heater pan drain. Is that correct?

[Ian Gills]

Isn't that where the bleed opening is on the shut-off valve? Normally there is a screw-thread cap on that (instead of a compression fitting and a pipe) which can be removed to drain the pipe down when the water supply is turned off and one wants to do some plumbing, or I suppose drain down for the winter vacation. I wonder why they have done this? Possibly to bleed the pipe down but I think it would leak when the water was turned on. What is stopping it draining at the other end?

Please do not tell me the bleed cap was leaking/missing and they did this instead of buying/tightening the cap.

I might try and do the same to run my icemaker!

I am sure it is not correct, but I am not an HI. The pipe and fitting risk a leak. But I would think it is an easy fix. Turn the mains off, remove the white pipe and add a cap.

And is that red PEX for the COLD supply line? Curious.

[Ian Gills]

Or is it in the wrong way round? If you put it in the wrong way the bleed port would be on the pressure side of the valve when it’s turned off. Look for the directional arrow on the body of the valve. The arrow should point towards the water heater end of the line.

I am just guessing now.

[Joe Funderburk, CMI]

Yes, red pex throughout. (Painted white at the shut-off valves under sinks.) Thanks for your comments.

[Ian Gills]

We could use some comments from a real plumber. Anybody?

[Joe Funderburk, CMI]

Originally Posted by Ian Gills

We could use some comments from a real plumber. Anybody?

I concur. Waiting before I send out the report. I did not un-tape the drain at the pan to see if anything was coming out.

[Bruce Thompson]

Hi Joe,

Concerning the first pic...Which way does the water flow? left or right?

I've had valves with similar setups (though always copper tubing). Generally they are just taking water from that spot and feeding something (icemaker in garage, etc...)

Based on the 2nd picture (which I guess is sideways) did the tube exit the drain pan line and go somewhere? Or could there be a reason for flushing the drain line?

Sorry I'm not much help, but I'm trying visualize this.
Bruce

[Joe Funderburk, CMI]

Originally Posted by bthompson1

Hi Joe,

Concerning the first pic...Which way does the water flow? left or right?

I've had valves with similar setups (though always copper tubing). Generally they are just taking water from that spot and feeding something (icemaker in garage, etc...)

Based on the 2nd picture (which I guess is sideways) did the tube exit the drain pan line and go somewhere? Or could there be a reason for flushing the drain line?

Sorry I'm not much help, but I'm trying visualize this.
Bruce

In the first picture, I believe the water is flowing to the right or in the direction of the handle toward the water heater.

The 2nd photo is looking down on the water heater drain pan. The drain tube is taped to an opening on the drain line for the drain pan.

[Ian Gills]

Then my guess is that water is constantly flowing out of that line. Could this be a crude attempt to reduce water hammer? Somebody knew you were coming!

I do not even know what water hammer is but my guess is that this would stop it!

[Marc D. Shunk]

What you have there has the appearance of a full port stop and waste ball valve, but it is actually a ball relief valve. These valves normally utilized on water heaters.

Your specific valve appears to be a Watts Regulator model BRV.


See page 23 of this PDF.

My concern is that the relief line, as small diameter as it is, may "whip" out of the drain tee if it is ever pressed into service.

[Ian Gills]

That's why I'm not a plumber!

[Joe Funderburk, CMI]

Originally Posted by Marc D. Shunk

What you have there has the appearance of a full port stop and waste ball valve, but it is actually a ball relief valve. These valves normally utilized on water heaters.

My concern is that the relief line, as small diameter as it is, may "whip" out of the drain tee if it is ever pressed into service.

I'm lost. I still do not understand the purpose of hte relief line. For what reason whould it ever need to be "pressed into service".

[Marc D. Shunk]

Originally Posted by jfunderburk

I'm lost. I still do not understand the purpose of hte relief line. For what reason whould it ever need to be "pressed into service".

Follow the link I provided to the .PDF document, and it will become clear.

[Ian Gills]

Heat-related pressure increase due to thermal expansion on the cold line. Sounds like global warming gone mad.

[Marc D. Shunk]

Originally Posted by Ian Gills

Heat-related pressure increase due to thermal expansion on the cold line. Sounds like global warming gone mad.

Nope, just regular operation of a water heater. After all, you've seen X-Trol tanks on water heaters? Traditional pressure relief valves? There is no check valve on the input nipple of a water heater, so any thermal expansion will be observed on the hot and cold sides of closed systems.