# Hot water coming out of cold faucet?



## Bill

I did a Moe's restaurant out in Blacksburg VA, and yes, it was right after the VA tech shooting and right next door. I had a call back because they had hot water coming from the cold faucets and toilets. I went bezerk trying to figure it out because we installed probably 300 plus linear feet of water lines, cold, filtered cold, hot, scalding hot, and tempered from the scalding ho lines, plus recirculating lines:furious: Man, trying to follow all that pipe drove me nuts and I could not figure out where it was coming from. Finally found the culprit. They had installed a "Y" from the scalding hot to the cold for the pre wash sink and they leave the faucets both on and controll it with a spray handle on the sprayer. This means there is an open line between the hot and cold sides which when someone flushed the scalding hot was siphoned through the cold line. Fixed it by installing a check valve on the cold side so the hot wont flow back. 

So if anyone runs into this problem check the sinks!


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## Plumberman

We have that problem down here at a hospital. We have had numerous leaks on domestic hot water. When we shut down the hot water to the building we have to fight the water all night because of all the mixing from the shower valves. As soon as someone opens a shower bam we are flooded again. When we go in at 6 we dont walk out of there untill 7:00 the next morning.... done it 5 or 6 times this year....


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## WestCoastPlumber

I had this happen at a local YMCA, it was on a chemical dispenser for the mop. When left on, it would make the womens showers cold, the check valve inside was bad. The thing was hidden in a closet, first night I walked the site, I found it, told the maint guy it had to remain off when not in use.

Well, with that fixed in my head, and out of my mind, the problem continued, I looked at 40 single handle shower valves, and faucets, temper valves, 10 tankless units, when I dfound no other problems, 6 long saturday nights later, he caslled me on the monday, said someone had opened the faucet, did not read the sign and left it on.

made me realize, check and double check, and go with my instinct.


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## Plumberman

Yep alot of times its the simplest things that throw me for a loop..... I feel ya on that one bro!


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## Ron

Watch for the pre-rinse faucet, they can cause bleed over when left on, T&S has a check side hot stem to prevent this.


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## 22rifle

When I read the title I thought: "Restaurant or cooking area sink with bad check valve or no check valve."

That's because of how many times I have run into this. First one ever threw me for a loop though.


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## Bill

22, this kitchen sink had no check valve. I informed the owner that to save future problems to let the architech know so he could not it on the plans when there is going to be something like that again. Lucky they do have one that installed at the cut off though.


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## DOESMITH

Here at our hotel in TN we have had this problem for months now. But only a hand full of rooms and not the same room every time. Me or my guys could not figure it out so we called 3 plumbers in and all 3 gave me different answers. We have been researching online for awhile now but today my assistant came across westcoastplumbers comment. So we cheacked our chemical dispensers on 2nd and 3rd floor. Sure enough both hot and cold was on and went into a Y with shut offs on the Y We crossed our fingers and shut off the actual valve and checked on a room with the hot water issue and it was fixed. It made plenty of since how the hot would run into the cold but it was something so simple that we never thought about it. And the rooms with the problems were right beside the room with the dispensers in them. All we can say is thank you to westcoastplumber for posting your problem that made us think about those dispensers and how they were ran.

Director of Engineering - Smith


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## SchmitzPlumbing

DOESMITH said:


> Here at our hotel in TN we have had this problem for months now. But only a hand full of rooms and not the same room every time. Me or my guys could not figure it out so we called 3 plumbers in and all 3 gave me different answers. We have been researching online for awhile now but today my assistant came across westcoastplumbers comment. So we cheacked our chemical dispensers on 2nd and 3rd floor. Sure enough both hot and cold was on and went into a Y with shut offs on the Y We crossed our fingers and shut off the actual valve and checked on a room with the hot water issue and it was fixed. It made plenty of since how the hot would run into the cold but it was something so simple that we never thought about it. And the rooms with the problems were right beside the room with the dispensers in them. All we can say is thank you to westcoastplumber for posting your problem that made us think about those dispensers and how they were ran.
> 
> Director of Engineering - Smith


more free advice given to handymen. most things on this site should be private.:thumbdown:


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## plumbdrum

A cross connection installed by an unlicensed individual on a soap dispenser. No surprise.


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## ShtRnsdownhill

DOESMITH said:


> Here at our hotel in TN we have had this problem for months now. But only a hand full of rooms and not the same room every time. Me or my guys could not figure it out so we called 3 plumbers in and all 3 gave me different answers. We have been researching online for awhile now but today my assistant came across westcoastplumbers comment. So we cheacked our chemical dispensers on 2nd and 3rd floor. Sure enough both hot and cold was on and went into a Y with shut offs on the Y We crossed our fingers and shut off the actual valve and checked on a room with the hot water issue and it was fixed. It made plenty of since how the hot would run into the cold but it was something so simple that we never thought about it. And the rooms with the problems were right beside the room with the dispensers in them. All we can say is thank you to westcoastplumber for posting your problem that made us think about those dispensers and how they were ran.
> 
> Director of Engineering - Smith


it only took this numbnuts 8 years to find this thread.........:laughing:


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## mpm

I started carrying T&S and Fisher check stems for this reason. Mop sinks and pre rinse faucets are known to cause this. Chicago faucets don't have check stems, they make wall unions with check valves in them though.


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## plumberkc

ShtRnsdownhill said:


> it only took this numbnuts 8 years to find this thread.........:laughing:



No you guys are the numbnuts for not understanding the Internet. This thread probably helped at least 100 other people with the same problem and will help hundreds of people in the future. Once you post something it's there forever. 


Sent from my iPhone using Tapatalk


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## ShtRnsdownhill

plumberkc said:


> No you guys are the numbnuts for not understanding the Internet. This thread probably helped at least 100 other people with the same problem and will help hundreds of people in the future. Once you post something it's there forever.
> 
> 
> Sent from my iPhone using Tapatalk


numbnuts was more for 1st post from non professional..not the content of the original thread...


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## plumberkc

ShtRnsdownhill said:


> numbnuts was more for 1st post from non professional..not the content of the original thread...


Definitely shouldn't have been directed at you. There are just so many guys here eager to show off their knowledge, too ignorant to realize they have just shared their "expertise" to average Joe's searching online.


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