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Heating, Air Conditioning, Fridge, HVAC/cold water leaking into heater hot water supply line?


2 floor I family home. I shut off cold water heater supply valve above water heater but draining water heater seems like was forever. Suspicious, after 2 or 3 hrs of draining I loosened hot water supply line union and was cold water under pressure coming out, so I closed the union and main water supply valve.Then after finishing draining, I disconnect heater from cold water pipe and then was trying to do the same to hot water supply pipe. However, the was still small stream coming out from it so I caped return pipe because I have no time to install new one but I need at list cold water to run the house. I will be ready to install new one tomorrow but what is worry me is how come I have small water pressure from every hot water valve on every faucet in the house at any given time? I have only one single hand faucet (in kitchen) on 2nd floor installed 3 years a go, thinking  broken cartridge might give leaking into hot water pipe pushing that water into each hot water valve on every faucet? Even that rest of them are single valve faucets. It is 3rd day now and I always have some, maybe 50% of cold water pressure from one (left side) and 100% from other on every faucet, dropping to just small stream after minute or so, just to build up the pressure again after a while.
Again; main valve is open and both heater lines are closed.
Can't figure it why and where from, cold water is going into all faucets hot water side valve, while heater is disconnected for 3rd day.
Seems, the situation was not screwing my hot water making, because my 9 years old heater last 14 !!!
But this is not my profession so I'm worry a little anyway.
Perhaps it might constantly adding cold water into hot water line, lowering water temperature in that line. Regards

I am by no means a plumber.  I work on A/C systems.  Clearly is seems somewhere this is a cross over where the cold water is getting to the hot water piping.  There are devices that can be installed in home that circulate hot water so there is hot water as soon as the spigot is turned on.  What I would do would be to shut off the hot water valve to each sink and see if the water pressure stops.  Then one at a time open valves to see if you can figure out where the cross over is.


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Craig HVAC Expert


I have been in the HVAC field for the past 18 years. I can help with most HVAC questions. I work on commerical buildings for the most part, and have yet to find anything I could not troubleshoot and repair, when repairable. I work on small 1 ton units to a 2500 ton chiller. Troubleshoot air flow, elect, and control problems. I attend regular classes to keep up with the latest and greatest.


I work on commerical sites, hospitals, gov't buildings. I can troubleshoot just about anything in the HVAC business.

5 years trade school, VFD training classes, Liebert factory training, some York and Trane factory training.

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