Heater Control Valve: Description and Operation

Heater Valve Location:

PURPOSE

The heater valve, which is located on the coolant inlet line, interrupts or allows coolant flow to the heat exchanger.

Heater Valve Sectional View:

CONSTRUCTION

The heater valve is constructed of high strength plastic and contains a vacuum operated rotary slide valve.

OPERATION

The heater valve opens to allow coolant to flow to the heat exchanger whenever vacuum is not present at the heater valve vacuum element, and closes whenever vacuum is present. The TCC control unit actuates the heater valve via the switchover valves when it determines the need for heat. In some modes the heater valve will be opened continuously and in other modes the control unit will switch it "ON" and "OFF" as necessary, to obtain the desired temperature.

NOTE: For this heating system the heater output is controlled by the position of the mixed air flaps and not by the position of the water valve in coolant circuit.