Cold water from an indirect water heater?

1.Hot water from the boiler enters the water heater (“COIL INLET”)and circulates through a coil, heating water in the tank before…

  1. Hot water exits the tank (COIL OUTLET) and heads back to the boiler to be re-heated.

  2. Upon demand from a plumbing fixture hot water leaves the tank through the “HOT WATER” pipe.

What’s the cold water pipe for?

Water could be too hot and goes through a tempering valve that adds cold water to bring it down to 120° for the home ? my guess never seen one .
. Cookie

The cold water pipe is to let water into the water heater tank.

I believe the coil inlet and coil outlet are for a coil inside the waterheater tank. The water, to be heated in the water heater, comes in the cold inlet and out the hot outlet and is heated by the water from the boiler running through the coil. :wink:

After looking at the picture I am sure this is correct Sorry . Cookie

In a one story house, the water pressure in the boiler is regulated down to 10-14 lbs and is totally separate from the domestic HW which is at street or well press.