GF83.70-P-3051F Flame Monitor Fault During Start of Heater Operation, Function

GF83.70-P-3051F Flame Monitor Fault During Start Of Heater Operation, Function
- with CODE (228) Stationary heater [models 203 up to 23.4.04, 215 as of 1.6.00 up to 31.8.02, 220 as of 1.6.00 up to 31.8.02, 209.3 up to 31.5.04, 230.4 up to 08]

Component Identification:

Function sequence
1. The activated heating mode is indicated by the indicator lamp in the STH switch (N72s12 or S46).

2. The control and operating unit (N18, N22 or N22/7) is switched to stationary heating mode.

3. The combustion air blower (A6m2) and the circulation pump (A6m1) start up. The combustion air blower (A6m2) operates approximately at its maximum rotational speed. The coolant flows through the heat exchanger (2) and the heater and cooling circuits.

4. At coolant temperatures below 30 °C the blower motor is switched off.

5. An inquiry of the glow pin unit flame monitor (A6r4) is started for approx. 1 s.

6. If the glow pin unit flame monitor (A6r4) signals the status "hot" = flame, the STH control unit or the STH or HB [ZUH] control unit (A6n1) evaluates this message as a defect of the glow pin unit flame monitor (A6r4), as flame formation cannot exist yet and immediately triggers the heater fault run-on period with subsequent fault shutoff for approx. 120 s.

7. The control and operating unit (N18, N22 or N22/7) changes from stationary heating mode to normal operating mode.

8. At the end of the fault run-on phase, the combustion air blower (A6m2) and the circulation pump (A6m1) are switched off, the indicator lamp in the STH switch (N72s12 or S46) goes out. Malfunction shutoff is present.

For starting up again, the STH heater unit (except model 220) or the STH or HB [ZUH] heater unit (model 220) must be switched off and on again with the STH switch (N72s12 or S46) after eliminating the cause of the malfunction.