Rheem Guardian Warm Water Owner's Manual And Installation Instructions page 20

TO FILL THE SYSTEM
To initially fill the system, follow the procedure below:

Open all of the warm water taps in the building (don't forget the showers).

Close the cold water isolation valve(s) at the inlet(s) to the thermostatic mixing valve(s) located inside the
warm water unit.

Progressively open the remaining isolation valves in the system including any isolation valves on the water
heating plant and the circulator(s).

Air will begin to be forced out of the taps. As water flows freely from each tap, close it.

Open the cold water isolation valve(s) at the inlet(s) to the thermostatic mixing valve(s).

Open the nearest warm water outlet, any remaining air will be forced out. Once water flows freely from the
tap, close it.

Check the pipe work for leaks.

Open the TPR valve on each water heater or storage tank, in turn, to check that each is filled with water.

Turn on the primary water heating plant.
IMPORTANT! TO ENSURE HOT WATER IS NOT SUPPLIED TO THE BUILDING PRIOR TO
COMMISSIONING, CLOSE THE ISOLATING VALVE AT THE OUTLET OF THE UV CHAMBER.
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INSTALLATION
20