Turn OFF the inline water supply valve. This valve is located in the tubing connection between the city water supply and the top of the brass regulator on top of the system.
Prior to re-opening office
Turn ON the inline water supply valve. The system must always have uninterrupted access to the cold-water supply for proper operation.
Because the coolant water level in the reservoir tank may be lower after an extended period of non-use, the water valve piston on top of the system should be cycled manually until water is visible leaving the 1/2” overflow fitting on the tank and running to the drain adapter.
This can be done by inserting a small screwdriver in the view-port hole on the brass stem of the thermal regulator on top of the tank and lifting up on the water valve piston. This ensures the reservoir is completely full of fresh coolant water.