18.0 Fault Finding
E
E20 or E50 - Temperature sensors faulty. Cold resistance approximately
10kΩ @ 25° C (DHW and CH sensors) 20kΩ @ 25° C (Flue sensor)
(resistance reduces with increase in temp.)
E28 - Incorrect PCBfitted
NO
Replace sensor or PCB(E28)
F 1.
Check and correct the connection of the tube between the venturi and gas valve
G
2. | Gas at burner | NO | Ensure gas is on and purged |
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PCB - X3 connector is 230V AC across | YES |
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Replace gas valve | |||||||
| terminals 1 & 2 |
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Ensure that the Hall Effect Sensor is in position. | YES | Check the voltage between red wire and blue | |||||
Check the connection between the PCB - X400 |
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| wire is more than 5V DC |
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connector terminals 3,6,7 and the electronic sensor |
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| YES |
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H
Check and correct if necessary
1.Ignition electrode and lead
2.Electrode connection
3.Spark gap and position
YES
Replace PCB
Voltage at PCB - X2 connector is at least 100V DC across terminals 2 & 5 (Note: from multimeter connect ‘common’ to 2 & ‘volts’ to 5). Check wiring
NO
YES
Replace Hall Effect Sensor
Replace PCB
Replace igniter
Burner
Viewing Window
7.5 ± 1
4 ± 0.5
10 ± 1
Electrode Position
56© Baxi Heating UK Ltd 2008