Hot Water From Cold Water Faucet

Originally Posted By: rmagee
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During a recent inspection I encountered a plumbing issue that I need some help with.

When I turned on the right tap, hot water came out. No problem I thought, hot and cold control positions reversed. I turned off the right lever and activated the left, guess what -- hot water.

I let the left run for a couple of minutes and still had hot water. I turned it off and let the right side run for a couple of minutes and eventually got cold water.

It was a hot day, so I figured maybe the cold water pipe was in an area where the air temperature would warm it. I want to point out that the first water out of the cold side was scalding hot, not just warm.

As I completed my inspection I encountered this same problem with every cold water control in the home, including the outside tap. The initial 30 seconds or so of water provided was scalding hot. After running the cold water the plumbing would only require about 15 minutes to heat up the cold water again.

The distribution system was copper, no cross connections I could find, no attic reservoir, no pipes in the attic and no pipes in exterior walls. I did not see any heat tape on pipes.

I used a voltage sniffer to see if maybe the pipes were energized but got negative results. Some of the connections were none conducting however.

Has anyone out there encountered this sort of problem before?

I covered myself in my report by stating "The initial water temperature from the cold water taps is very hot and has the capacity to cause injury. Consult a plumber."

At this point I am open for suggestions.

Rick Magee
Building Check Ltd.
Fredericton, N.B. Canada
"check with a professional"

Originally Posted By: rmoore
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Just a wild guess…intake and outake at the water heater mis-connected? Hot water from the top of the tank could be convecting back into the cold feeder piping.

Richard Moore

Rest Assured Inspection Services

Seattle, WA

Originally Posted By: jpeck
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When you turned the hot water on, did you have hot water almost right away?

If so, here is a WAG - they may have an auto recirculating system which circulates the hot water back through the cold water lines, only the cold is not supposed to get that hot. autocirc system.

Someone may have seen this system and figure they could make their own with their own pump (which pumps too much water too fast).

Like I said - a WAG.

I was thinking about all the pipes being in the attic or exterior walls ... until you said they were not.

Jerry Peck
South Florida

Originally Posted By: gsutterfield
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Saw this once in an eye wash station. Unit had been installed at a hand wash sink at the nurses station of a residential care facility to meet code. Mixing valve went bad and charged the cold water side with hot water. Sadly it was not discovered until the eye wash station was used. Had they been performing routine checks I suspect no one would have gotten hurt.

Originally Posted By: jstevens
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hi guys and girls

heres one for you i have the same thing in my house hot comein from cold .it is not scalding but it is hot here in fl. i have a well and the cold water pipe heats up when it is not used for a while from the sun .so maybe the pipes in your house are from a well or they are near the top of the soil let me know