Hot water in cold water pipe

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Thejaxx
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Hot water in cold water pipe

Post by Thejaxx » Sun Dec 03, 2017 12:05 am

Hello,

Found you through YouTube and had two different questions, so I’ll use two different posts.

We have a 94 year old house that was replumbed when purchased with all copper pipes six years ago. Only minimal maintenance has been needed, such as flushing the water heater, replacing drain valve on the heater and pressure release testing.

A few weeks ago, we started to notice hot water (not warm) coming out of the cold side all through the house. It would clear up after a min, but would be back pretty soon. I’ve noticed the cold water pipes become warm, but the hot would be cold if left alone for an hour or so. The expansion tank is on the cold side and there are heat traps internally and on the cold.
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7BE23094-7661-487C-A1FA-F8E72ADA765A.jpeg (146.72 KiB) Viewed 41 times
The water heater is 9 y/o and the temp is set to about 140.

Any ideas?


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A. Spruce
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Re: Hot water in cold water pipe

Post by A. Spruce » Sun Dec 03, 2017 2:09 am

My guess would be that the dip tube may have corroded through, but I'm no waterheater expert.
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Shannon
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Re: Hot water in cold water pipe

Post by Shannon » Sun Dec 03, 2017 8:48 am

Sorry but what are the "heat traps " you refer to?
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Thejaxx
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Re: Hot water in cold water pipe

Post by Thejaxx » Sun Dec 03, 2017 10:41 pm

Here’s a primer that taught me what they do.

https://youtu.be/SxU8lnhaMx8

Most common is the inverted U, just like a P trap, but keeps hot water from cold line. Other is a nipple heat trap, that either has a ball or flap.

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Shannon
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Re: Hot water in cold water pipe

Post by Shannon » Mon Dec 04, 2017 7:40 am

It is possible that the Dip tube is rotted off and could be changed ,I would start with checking that. I'm not convinced that this is your problem but it is easy to check and cheap to fix.
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