GF83.70-P-4205TX STH Switchover Valve, Component Description

GF83.70-P-4205TX STH Switchover Valve, Component Description
- with CODE (228) Stationary heater

Component Identification:

Location
The STH switchover valve is next to the STH heater unit, which is located in the front area of the right wheelhouse.

Task
Actuated by the STH control unit (A6n1), the STH switchover valve controls the flow of coolant (small or large coolant circuit).

Function
The STH switchover valve is a solenoid valve that is actuated by the STH control unit (A6n1) and controls the flow of coolant (small or large coolant circuit).

Coolant temperature below 60 °C (heating mode started)
The STH switchover valve is permanently actuated and therefore only enables the small coolant circuit.

Coolant temperature 60 °C or above (heating mode started)
The STH switchover valve is pulsed. This causes the large cooling circuit to be heated as well.

No heating
The STH switchover valve is open (not actuated) and enables the large coolant circuit.