SAAB WIS ONLINE

Heater operation

Heater operation


Turning on the heater causes the water pump to start and after a certain initial fuel supply and glow-plug preheating sequence, combustion is initiated by the combustion air fan, glow plug and fuel pump.

When the flame has stabilized, the glow plug is disconnected after a certain time.

As necessary, the control module sets the heater to the following positions:


• POWER - 4000 W

• HIGH - 3300 W

• LOW - 1500 W

• OFF


The temperature thresholds are programmed in the control module.

If the heat requirement at ”LOW” is so low that the temperature of the coolant rises to 86°C, the heater will switch over to standby mode. Following this, the combustion air fan will continue to run for about 100 seconds. The water pump continues to run until heater control is resumed.

When coolant temperature drops below 75°C, the heater switches to the ”HIGH” position again.