Cold water coming through the hot water pipe

[EEshorts]

Hello,

I am at a new home construction site. The home has a hot water recirculation line install with the hot water tank is not hooked-up. Wanted to install a working toilet.
So, I installed a shut-off value on the cold-water supply to the hot water tank. When I turn-on the house water supply line, water comes out of the hot and recirculation lines.

Is this because on the shower values letting cold water back into the hot water line???

Thanks,

 

[Geofd]

Can you feel the hot water right back to the meter????when you say the hot water is not hooked up do you mean the fuel that makes the hot water or some off the hot water piping,sometimes when there is no use but the circular is running ,if there is no check valve hot water will be pushed into the cold side

 

[EEshorts]

Can you feel the hot water right back to the meter????when you say the hot water is not hooked up do you mean the fuel that makes the hot water or some off the hot water piping,sometimes when there is no use but the circular is running ,if there is no check valve hot water will be pushed into the cold side

This is brand new construction, so the hot water tank has not been hooked-up to the cold water supply. So I don't understand how turning on the cold water supply to the house would cause water to come out of the house hot water line since the tank is not connected.

 

[Twowaxhack]

Hello,

I am at a new home construction site. The home has a hot water recirculation line install with the hot water tank is not hooked-up. Wanted to install a working toilet.
So, I installed a shut-off value on the cold-water supply to the hot water tank. When I turn-on the house water supply line, water comes out of the hot and recirculation lines.

Is this because on the shower values letting cold water back into the hot water line???

Thanks,

If the shower valves do not have the cartridge installed and turned OFF, yes they will cross over hot and cold and become one big water system.

The shower valves may have integral stop valves. If so there will be a screwdriver style stop valve on the shower valves hot&cold inlets.

 

[EEshorts]

If the shower valves do not have the cartridge installed and turned OFF, yes they will cross over hot and cold and become one big water system.

The shower valves may have integral stop valves. If so there will be a screwdriver style stop valve on the shower valves hot&cold inlets.

Yes, that makes sense. I can see the shower valves only have a cap on them, Thank you!