Heater Circuit Function - GF83.20-P-2003KJ

MODEL 453.0 (except 453.091), 453.3 (except 453.391), 453.4 (except 453.491) 

Function requirements, general 

• Engine running.

Heating circuit, general 

The coolant pump pumps the coolant through the engine. The coolant absorbs the engine's heat and becomes heated.

Then, part of the heated coolant is routed through the heater heat exchanger, the heat of which is given off into the blowby interior air. Most of the heated coolant does not flow through the heater heat exchanger, but from the engine to the coolant thermostat. Depending upon the coolant temperature, the coolant thermostat guides the coolant through the radiator or directly through the engine again.