# crossover



## joecal (Jul 17, 2012)

Hello.  I'm having a problem with hot water coming out of my cold water taps at times (even ones that have two handles).  From what I've read, single handle faucets and valves that have become defective can cause this.  Sometimes, once it starts, the hot water doesn't finally cool down after I let it run for a while.  Other times, it'll cool down after a while.  I'm not talking warm but hot water.  I have a hot water heater and two showers with single handle valves (one is a moen) and I have a single handle Kohler forte faucet with one of those heads you can pull away from the unit.  Since my Moen shower valve was leaking anyways I had my plumber replace the cartridge and now it no longer leaks.  He felt inside the pipe where the cartridge goes into before he put it in to see if he could feel any grooves (which would allow water to pass he said) but said it felt ok.  The new valve he put in was plastic.  However, my crossover troubles still continue.  I just got done turning on the kohler kitchen faucet and the water was coming out the tap was hot so i reached under the sink and felt the hot water line but it was cool, and the cold water line was hot.  So it seems to me that the hot water wasn't coming from the hot water side of the kohler unit but from the cold water line itself.  This leads me to believe that the odds are against there being a problem with the kohler faucet.  However, that still leaves one other shower single handle valve (which I took a photo of and my local plumber supply store said was plastic and which they claim wouldn't be a cause of crossover since it was plastic).  Is there any other trouble shooting anyone can recommend or any way that I can check the other shower valve (which is enclosed so i can't feel the hot and cold water lines.  Also, I felt both lines feeding into my hot water heater and while the hot water line out was warm the cold water line in was also warm.  Is it possible that the hot water may be coming back out of the hot water heater and going into my cold water line?  Also, I have a clothes washer with a hot and cold line but it has two valves, one for the hot water and one for the cold water so it didn't seem possible to me that crossover could be happening there?  Any suggestions would be much appreciated.  Thank you.


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## nealtw (Jul 17, 2012)

If you have not run any water for a while, all water will be cool when you first turn it on. Run the cold water in the kitchen until it gets warm and then feel the the hoses at the washer and turn on each cold water in the house one at a time. Wherever you find instant hot water that will be the guilty guy.


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## joecal (Jul 17, 2012)

Hello Nealtw, thanks for the response.  I'll give that a try.  If I understand what you're saying tho, it's possible that even a regular two handled faucet could be to blame?   Thankss again, Joe


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## joecal (Jul 18, 2012)

nealtw, I did what you recommended two times.  It took a while because most of the time the water comes thru cool as it should through the kitchen faucet and other faucets.  Two times now it's come thru hot at the kitchen faucet.  Both times this happened I felt both lines to this faucet and the hot water line felt cool but the cold water line felt warm.  So I went and checked the cold water line into the washer and it was cool.  I turned on all the other faucets in my bathrooms and utility room and the showers and they all felt cool.  When I checked at my cold water line into my water heater it was hot.  Is it possible that the hot water may be backing out of the hot water heater into the cold water line at times?  Thankss, Joe


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## nealtw (Jul 18, 2012)

Do you or have you had a circulating pump hooked up?


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## joecal (Jul 19, 2012)

nealtw, don't know.  From what I've read that's a pump that provides nearly instant hot water.  But we've never had instant hot water in the 8 months that we've lived in this house so if there is such a pump it's never worked.  I looked in the closet where my water heater is at but I don't see anything other than the cold water line into the top of the water heater and the hot water line out the top and one other line coming out the side of the heater that I figured was the pressure release valve with a pipe that goes into my wall.  Is there any way I can check myself to see if I have one of these circulating pumps?  Thanks, Joe


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## joecal (Jul 19, 2012)

nealtw, ok I looked on line and I see that that device is installed on the hot water line near where it exits the hot water heater and then there are connecting devices that you put under a sink which connects the hot and cold water.  I don't have anything like this on my hot water line out of my hot water heater.


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## joecal (Jul 19, 2012)

nealtw, i just took a good look under my kitchen sink and there is a box called an in sinkerator instant hot water dispenser.  Now I didn't think it was an issue since I unplugged it when we moved in 8 months ago.  I see it has a line from the cold water side but if it's unplugged I don't see how it could heat up the cold water.  And as far as I see I don't see anyplace where the hot water line feeds into it.


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## nealtw (Jul 19, 2012)

As you might guess, I am quickly running out of questions to ask. Turn off the infeed to the tank, do you get cold water then? If yes turn it back on and turn of the hot stop under every sink and washer and see if that corrects it at the showers.
It must be nice sitting on a worm toilet.


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## Garmo (Aug 7, 2012)

JoeCal - 
it is quite possible that your internal parts to one of your single hand faucets (shower would be most likely based on flow volume) is cracked inside allowing the water to cross over.  You said one is Moen, do you know who the mfg is on the other one? Since the Moen parts were just replaced i would rule out that one, unless that is when the issue began.


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## joecal (Aug 8, 2012)

Garmo, Thanks for the reply.  Here's the latest:  I ended up closing all the single handle faucets except for one which was stuck and the problem continued.  And I closed off the clothes washer too.  So I figured it was the hot water heater letting water go backwards into the cold water line or my other shower or one faucet that I couldnt close since the line was stuck.  I had a plumber come by and he says it's the handle to the other shower that's causing the problem.  I don't know how he determined that since my wife says he didn't turn off the water supply.  Possibly he checked the water heater and verified it was ok and the other faucet also must've checked out.  What I'd like to know is if he's sure.  He didn't give me any more info that that but I wonder if the cartridge may just need to be replaced.  He says the entire housing needs to be replaced but again I don't know how he'd know that if he didn't take out the cartridge and check the inside.  When my other plumber put a new cartridge into my first shower he felt around inside to make sure it had no cracks or gouged areas.  I don't mind paying to have the whole unit replaced if it's really that (big bucks) but If it's only the cartridge I don't want to have to have to replace something that doesnt need replacing.  Thank you for your help and suggestions.  Joe


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## joecal (Aug 9, 2012)

Well, after doing a little research, I went and bought a water pressure gauge with a lazy hand. I installed it on the outside water spigot to see what the pressure was there. It was 122 which is a lot higher than 80 so I guess I need a need regulator. I'll leave it there for 24 hours to see where the lazy hand goes. Then I'll screw it into my hot water heater spigot to check the pressure there. What I'd like someone's opinion on is if my pressure is too high from the outide or if I'm having thermal expansion (from the water heater) could that cause backflow into my cold water line from my water heater and be responsible for my crossover problem? Thank you


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## nealtw (Aug 10, 2012)

I doubt it, run your cold water in the shower untill you get hot water there and go feel the pipes at the tank. I would be awlfully surprized if the cold infeed was hot.


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## joecal (Aug 10, 2012)

nealtw.  Yes, I already did that and it was hot.  Matter of fact the cold water line into the hot water heater has been consistently hot.  I don't have one of those thermal expansion tanks.


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## nealtw (Aug 13, 2012)

I found this discussion, perhaps you will find it informative.
http://ths.gardenweb.com/forums/load/plumbing/msg1101165611579.html


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