End heater operation, function

W83.70-0109-06

1 Heater unit

2 Heating air inflow vents

3 Combustion and heated air blower

4 Control IC

5 Flame sensor

6 Glow pin

7 Burner insert

8 Temperature limiter

9 Afterburner pipe

10 Heat exchanger

11 Fuel metering pump

12 Timer

13 Rotary potentiometer

A Exhaust

HA Heater outlet

HE Heater inlet

V Combustion air

Terminate heating mode from partial or full load

Requirements

 The heater's (1) heating mode is switched on at the timer (12).

 The heater (1) is in the full load or partial load range.

Terminate heater operation

Heater operation is terminated:

 by switching it off manually on the timer (12), or

 because of an automatic shut down initiated to prevent impermissibly high operating temperatures (> 140 °C). In doing so the temperature limiter (8) records the excess temperature and issues a signal to the controller board (4).

In both instances the controller board (4) interrupts the fuel metering pump's circuit (11) and the heater (1) switches into power-down:

- The combustion and heated air blower (3) continues to run for 35 seconds at 60 % of the maximum speed. This serves to cool the combustion chamber and purge it of combustion gases.

- As soon as the flame monitor (5) detects "Flame out", the combustion and heated air blower speed are increased to maximum speed for 60 seconds.

- After this during the ensuing 60 seconds the speed of the combustion and heated air blower (3) is reduced in stages to "zero".

Once the power-down phase is over all heater (1) components are switched off.

Terminate heater operation from the control interval mode

Prerequisites

 No fuel is being delivered, or

 the heater (1) is in the control interval mode.

Terminate heater operation

The heater (1) is switched off immediately without starting the power-down mode.