Why is cold water running out of my hot water line after disconnecting water heater?
TryToHaveFun asked:
I’m in a pinch! I am trying to install a new tankless water heater, so I have my old tank removed and the cold valve coming in turned off. I turn back on my cold water to the house and everything is OK, but then after a bit water starts trickling out of the open hot water line. Anything I can do to get my cold water working for now? What’s causing this?
Lashandra
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I’m in a pinch! I am trying to install a new tankless water heater, so I have my old tank removed and the cold valve coming in turned off. I turn back on my cold water to the house and everything is OK, but then after a bit water starts trickling out of the open hot water line. Anything I can do to get my cold water working for now? What’s causing this?
Lashandra

April 2nd, 2009 at 9:27 pm
Davida
There’s no heat.
April 5th, 2009 at 3:55 pm
Gabriele
its mixing through a valve somewhere
in this situation its normally a single handle shower valve that causes it. Shut the main off and you’ll be fine
April 5th, 2009 at 7:14 pm
Arleen
All the water comes in from the cold side so if you open a hot water faucet cold water will come out the hot side. However if you turn the cold water valve off at the tankless coil (feed side )this should remedy your problem. If not the valve is bad and you should install a new one
April 5th, 2009 at 7:45 pm
Geoffrey
If you just want to get the cold on, add a valve to the open end hot line. or just cap it. If you valve it you wont have to turn the water off to install the water heater. The cold water is making its way into the hot at your single handled faucets or shower.
April 6th, 2009 at 1:46 am
Emilie
this means that one or more of your hot water faucets are leaking cold water through them.. make sure they are all turned completely off..
this occurs because there is no pressure in the hot water lines. if a hot water valve is not completely seated then cold water will run through your spout and also into the hot water line since there is nothing from keeping it from doing so.. you have to cap your hot water line.. or you might try shutting the hot water valves under your sinks.
April 6th, 2009 at 2:10 am
Ariel
Are you saying that it is leaking from where you disconnected the hot water system? The taps that isolate hot water systems rarely work properly. Replace the tap or cap it off. Those taps make it a prick of job when I have to replace elements!