Cold water coming through the hot side?


  #1  
Old 07-23-14, 01:23 PM
A
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Cold water coming through the hot side?

Hey guys, this is my first post and just want to say thanks in advance...

Here's what I am experiencing:

I am installing an Ecosmart Eco27 Tankless water heater in my house. I currently have the old tanked heater (which went out), removed and the water turned off from the cold side by the turn off valve next to the tank....

All 3 pipes are unconnected (hot, cold, and drain that had the PRV hooked to it)

I have 3 showers, 3 sinks, 2 tubs (and possibly some toilets hooked to this hot water heater)

Heres the issue:

When I turn on one of the sinks, the cold water starts coming through the unconnected hot side (the one that would normally go into the 'hot output' of the tank) in the attic!! I have a bucket under it now because I was testing everything and when I would turn on the cold side of that one sink, water would start gushing through the hot....

No other sinks, tubs, or faucets do this....

OMG, I think I might have a possible reason for this that I just thought of while writing this lol....

I have a washer/dryer tee-ed off that sink line that is causing this....

Is there some way that the washer/dryer that is split off from this could be causing this?

Thanks,

Aaron
 
  #2  
Old 07-23-14, 02:26 PM
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I shut off the hot water valve underneath the sink, and now it is not doing it (meaning coming through the hot water pipe in the attic that was connected to the hot water heater output)

What would cause this?
 
  #3  
Old 07-23-14, 06:44 PM
Z
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All faucets allow you to mix the hot and cold water. When the hot water line has no pressure, the cold water can backflow to the hot line. Any faucet could do this.

That's why you need to cap or shut off both the hot and cold lines when removing a hot water heater.

Hope this helps!
 
 

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