Wasting warm water woes - Stop a leak on my hot water heater.
April 14, 2012 4:16 PM   Subscribe

Indoor Plumbing Filter: Help me understand a valve on my hot water line and how to stop a leak.

Hi everyone. Our hot water heater has a seemingly pointless valve on it that appears to be leaking. Here's a photo of the valve, with the attached plastic piping. The valve handle will turn 45 degrees clockwise and stop, with no change in the flow of water to the pipe. I left it in the position it was in when we moved in. FWIW the house is relatively new construction, around 2008 or 09.

The plastic tubing goes from the valve straight down to the floor, near the floor drain (photo). It used to end a few inches above the floor, where it would drip occasionally. I hate the thought of wet concrete and splashing water, so I bought a coupler and added a few inches of piping to run it down into the floor drain. You can see the mineral stain where it used to drip. The white PVC in the photo is the central air conditioner humidity drain, btw.

Anyways, the other day I was down in the basement and could hear the sound of water running. I pulled the end of the plastic piping out of the floor drain and holy crap was it running. I took a video to show you the flow. FWIW the water that comes out is warm. I have no idea how long it's been going on for since our water bill isn't metered, but at least 6 months since I last pulled the end out.

Now, I realize having it run into the drain isn't hurting anyone BUT I hate the thought of wasting copious fresh water (doubly since we live in a desert area), I hate paying to heat water that is just running down the drain, and I don't want this to get worse or have some flooding if the floor drain gets clogged, etc.

So, my questions:
1. Why is this valve even here? To drain the house hot water lines or something? Pressure release?
2. Why is the valve leaking? Mostly I want to know this for educational reasons on my own part. I assume it could be a worn washer (if there even are washers in this style of valve) but this valve is never touched, so how would it wear out? Or is just a ball valve and the handle isn't turning the ball inside? Is it just something that needs to be tightened?
3. And the main question - How do I stop the water flowing? I thought about buying a cap for the place where the plastic tubing screws on and just capping it off, but I wasn't sure if a) it would hold line pressure and b) if there was some reason this valve needed to release water.

Anyways, thanks in advance for your help.
posted by msbutah to Home & Garden (8 answers total)
It looks like a cut-off valve that would be used during replacement of the water heater. Since you cannot turn it 90º (you said it turns 45º) that valve should be replaced. Since you said the white tubing goes near to the floor drain that might be a pressure relief valve. If so it is corroded inside. I have not seen a pressure relief valve like that but that is what it must be. If you can cut off the whole house water supply you might be able to take that valve off and get a replacement at a supply store. If you don't turn off the whole house you will likely have a flood of sorts.
posted by JayRwv at 4:54 PM on April 14, 2012

Do not cap off that tubing. That is asking for trouble. The water has to go someplace.
posted by JayRwv at 4:55 PM on April 14, 2012

Best answer: That is the supply valve pressure relief valve and I believe it is installed incorrectly when the valve is closed the tank shoul "see" the pressure releif valve , the plumber installed it upside down this is potentially dangerous ,
posted by hortense at 4:59 PM on April 14, 2012

Water will flow from the pressure relief tube regardless of the shut off valve, to stop the flow from the relief valve tube shut the water off upsteam of the water heater. That is the cold water supply line to the tank if you close this valve your hot water tank will operate without a pressure relief valve.
posted by hortense at 5:06 PM on April 14, 2012

Response by poster: Ack really? Here's another photo of the setup far back. And the valve reads "Watts Regulator 0643" on the handle. I found a PDF detailing the proper install, and it does appear to be installed backwards. I guess I'll have the house owner (we're just tenants) call a plumber.
posted by msbutah at 6:06 PM on April 14, 2012

Best answer: Besides the valve being upside down the extension you put on the drain line is installed in an illegal manner. You need to have an air gap between the potable water system of the valve and the non potable water in your sewer system. As it is now a sewer back up combined with a loss of water system pressure could result in contaminated water being sucked into your potable water system and, worst case, a significant disease vector.
posted by Mitheral at 6:37 PM on April 14, 2012

Best answer: Looking at your third system pic that valve may be installed correct. You have a separate temperature and pressure relief in the side of your tank which is protecting your water heater from going kablooie. The valve that is leaking might be there to provide pressure relief of the system down stream of the hot water tank. Looks like there is a recirc pump hiding behind the flue in that picture; if you also have demand heaters or make up heat in the recirc system then you'd need pressure relief in that location.

PS: You need to secure what appears to be an electrical cord that is resting on the flue pipe away from the flue pipe. Even B-Venting can get hot enough to degrade electrical insulation.
posted by Mitheral at 6:47 PM on April 14, 2012 [1 favorite]

Response by poster: Thanks for pointing those out. To be safest I told the owner who will call a plumber about it. I tied up the excess cord (that runs the pump that's back there) and modified that drain bit so there's a gap again. Thanks for the info folks. I learned a lot!
posted by msbutah at 8:04 PM on April 14, 2012

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