Junkers PCB ZWB28 3C Cerapur Smart Ref. 8748300941
RefurbishedJunkersPCBs (control boards)

Junkers PCB ZWB28 3C Cerapur Smart Ref. 8748300941

80 €VAT includedIn stock · 2 units

PCB (control board): refurbished spare part that controls the ignition, modulation, and safety features of the boiler. Useful if the boiler does not ignite, locks up, or the display is unresponsive. Compatible with ZWB28-3C23, ZWB28-3C31, ZWB28-3CE23 (ref. 8748300941). Includes a one-year warranty and delivery within 2–4 working days in the EU.

1
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Delivery in 2–4 working days
1-year warranty
14-day return
Technical support

Key Data

Reference
8748300941
Brand
Junkers
Type of part
PCBs (control boards)
Available units
2 units in stock
Status
Refurbished
Warranty
1 year
Shipping
2–4 working days (EU)
Return
14 days

The same part (ref. 8748300941) equips these models. Verified compatibility; check the reference before purchasing.

Junkers Cerapur Smart ZWB28-3C

  • ZWB28-3C23
  • ZWB28-3C31
  • ZWB28-3CE23
  • ZWB28-3CE31

Neckar NWB24-3C

  • NWB24-3C23
  • NWB24-3CE23

Fault codes related to this part (not the entire boiler). They usually have more possible causes: first rule out electrodes, wiring/connections, and gas supply. Verified with ≥3 sources.

CodeWhat does it mean?Cause and diagnosis (this part)
F0Incorrect reference voltage (internal electronics error).The PCB (Heatronic/"control unit") may lose internal references or fail; check service parameters (8.d/8.C), wiring, and if it persists after resets and checks, replace the PCB.
EAFlame not detected during ignition.If gas, electrodes, and wiring are correct and the ionisation current is low/erratic, an electronic fault in the PCB (ignition/ionisation reading) may prevent flame detection; measure ionisation µA and, if after the diagnostic tree it persists, replace the PCB.
C6The fan does not start / fan fault/airflow.After checking the connector, power supply, and fan, the manual indicates "electronic fault" and change of PCB; also in Bosch documentation, it is advised to check connections on the PCB and, if necessary, replace the 'control board'.
A7Defective DHW NTC sensor.If the NTC and the harness ('baum') measure correctly even from the 20-pin connector, the reading circuit on the PCB itself may be faulty; measure the NTC at the sensor and on the PCB, and if there is an 'electronic fault', replace the PCB.
How do I know if this PCB is for my boiler?
Verify the reference 8748300941 printed and ensure your model is on the list of compatible ones; also compare the connections with the original part.
What is it used for?
The PCB controls the ignition, modulation, sensor readings, and safety features of the boiler.
Is the boiler not igniting, locking out, or is the control board unresponsive?
After ruling out mains voltage, fuse, and connectors, a damaged PCB causes lockouts, blackouts, or erratic display. Repair the external cause before installing the new one.
Which models is it suitable for?
Part shared by various models (see Compatibility). If your model does not appear, send us a photo of the marking and we will confirm it.
Installation and recommendations
After installation, a technician must adjust the service parameters (type of gas, power settings) and check combustion and safety features.
What does refurbished mean and what coverage does it have?
Part removed from a boiler out of service, inspected and tested. Includes 1-year warranty and 14-day return policy. Delivery within 2–4 working days in the EU.
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