"Start heater operation" function

W83.70-0109-06

1 Heater
2 Hot air intake
3 Combustion and hot air blower
4 Control circuit board
5 Flame monitor
6 Glow pin
7 Burner insert
8 Temperature limiter
9 Combustion tube
10 Heat exchanger
11 Fuel metering pump
12 Timer
13 Rotary potentiometer

HE Hot air inlet
HA Hot air outlet
V Combustion air
A Exhaust

Function sequence "start heater operation"

 The heater (1) can be started up manually with the timer (12) for the heater or automatically by the timer when set.

 The combustion and hot air blower (3) and glow pin (6) are started.

 The combustion and hot air blower runs for 1 second at 90 % of maximum speed (break-loose torque) and is then reduced to 30 %.

 The air sucked in passes by the temperature sensor:

- If the temperature of the air sucked in is greater than the set temperature, only the combustion and hot air blower continues to run (controlled shut-off phase).

- If the temperature of the air sucked in is lower than the set temperature, the starting operation begins.

 After approx. 20 seconds the fuel metering pump (11) starts pumping fuel. A fuel/air mixture is formed in the combustion tube (9), which ignites on the glow pin.

 After an additional 25 seconds the speed of the combustion and hot air blower is increased to 60 % of maximum speed within a period 20 seconds and the fuel metering pump increases the quantity of fuel proportionally.

As soon as a flame is recognized by the flame sensor, the combustion is stabilized (see stabilization).

 If proper combustion is not present within 120 seconds, the speed of the combustion and hot air blower is increased with the glow pin switched on and fuel metering pump switched off and the starting operation is repeated automatically.
If combustion is still not present after 80 seconds, the system goes to malfunction switch-off and the combustion and hot air blower continues to run for 120 seconds at maximum speed.

Function sequence, stabilization

 After an additional 20 seconds the speed of the combustion and hot air blower is increased to maximum speed within a period of 17 seconds and the fuel metering pump meters fuel proportionally.

 After 102 seconds the glow pin is switched off.

 If the flame goes out during the increase in output, the starting procedure is repeated.

 If stable combustion is present, the auxiliary heater operates at maximum output.