Start heating function

W83.70-0142-09

1 Fuse

2 Warm air blower

3 Controller board with temperature sensor

4 Combustion air and heater blower

5 Combustion air blower

6 Glow plug

13 Fuel metering pump

14 Timer

A Fuel supply line

B Combustion air inlet

C Exhaust outlet

D Cold air inlet

E Warm air outlet

7 Overheating sensor

8 Burner insert

9 Flame sensor

10 Afterburner pipe

11 Heat exchanger

12 Jacket

"Start heating" function procedure

 Heating is switched on at the heater timer (14) or by means of preselection.

 The glow plug (6) is started. The combustion air and heater blowers (5, 2) start up at slow speed.

 If the heat exchanger (11) temperature is higher than the selected interior temperature, only the blower (cold blowing phase) runs to start with. Once the residual heat has been removed, the starting procedure begins.

 The fuel metering pump (13) starts to deliver fuel after approx. 15 seconds. A fuel/air mixture forms in the afterburner pipe (10) and ignites at the glow plug (6).

 The blower speed and the fuel quantity are continuously increased.

 When a flame is detected at the flame sensor (9) and combustion has stabilized, the glow plug is switched off (6). The fuel/air mixture then ignites independently at the hot combustion chamber walls.

 If no proper combustion occurs within 90 seconds the above-mentioned starting procedure is repeated. If the heater does not ignite after a further 90 seconds an abnormal shutdown takes place.

 If the flame goes out of its own accord during operation, a new start initially takes place. An abnormal shutdown also takes place if the flame goes out again within 15 minutes.

 During stable combustion the auxiliary heater operates at maximum heating power at the "POWER" control setting until the selected operating temperature is reached.