Junkers PCB ZWBC 25-2 C 23 Cerapurcomfort - Ref. 8748300923
Control board for Junkers and Bosch boilers from the ZWB/ZWBC series (Cerapurcomfort). An Omron relay with code 8 737 702 723 is mounted on the board. It also has an attached label with the text Compur Control, without indicating whether it identifies the entire board or just that component.
VAT included
Consult via WhatsAppBosch Junkers boilers compatible with reference 8748300923
PCB with reference 8748300923. Four confirmed compatibilities: ZWBC 24-2C and ZWBC 25-2C.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Bosch Junkers ZWBC 24-2C | Cerapur Comfort ZWBC (2C) | Contrasted |
| Bosch Junkers ZWBC 25-2C | Cerapur Comfort ZWBC (2C) | Contrasted |
| Bosch Junkers ZWBC 28-2C | Cerapur Comfort ZWBC (2C) | Contrasted |
| Bosch Junkers ZWBC 30-2C | Cerapur Comfort ZWBC (2C) | Contrasted |
Can't see your model or have questions? The printed reference takes precedence. How to check it · Send us a photo via WhatsApp.
How to check if ref. 8748300923 is the part for your boiler
What determines it is not the boiler model, but the reference printed on the part you already have installed.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 8748300923. If it is not visible, do not identify the part from its shape alone.
- Check the full boiler model on its data plate and look for it in the model associations on this page.
- Compare the connections and physical body with the original part before installation.
- If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Symptoms and faults that the PCB 8748300923 resolves
The PCB controls the ignition, modulation, and safety features of the boiler. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
You can hear the relay click, but the pump or the fan does not start.
Cause: A worn relay can close the contact without sending enough current to the component it is supposed to activate.
With the boiler off, measure the continuity at the relay output when it is activated, before replacing the PCB.
- 02
The boiler is locking out with a fault code related to the burner.
Cause: The PCB manages the ignition and flame control; an internal fault can cause a lockout even if the burner is functioning properly.
Check the ionization electrode and its wiring before assuming that the fault is with the PCB.
- 03
The control panel does not respond to any button presses, even though the boiler is powered.
Cause: The microcontroller on the PCB processes the button presses from the panel; if it hangs, it stops functioning.
Try a complete reset (power cut for several minutes) before ruling out the PCB.
- 04
The boiler turns on and off by itself several times in a row.
Cause: Repeated cycles of turning on and off usually indicate a fault in the control board or in the relays it manages.
Check if the cycle matches the demand for domestic hot water or heating, to determine if the source is in the PCB or in another sensor.
Fault codes for Bosch Junkers that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F0 | Internal error. | The PCB (control board) has an internal fault (e.g., A/D converter, memory, or power supply), triggering the "F0". Check voltages and wiring, encoder connections, and if the error persists after reset and testing, replace the PCB 8748300923. |
These symptoms can have more than one cause. If your boiler displays a fault code, send it to us via WhatsApp along with a photo of the labeling, and we'll tell you if this is the part.
Data sheet for the Bosch Junkers PCB 8748300923
- Catalogue reference
- 8748300923
- Brand
- Bosch Junkers
- Type of part
- PCBs (control boards)
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- Code of the relay/contactor mounted on the PCB.
- 8 737 702 723
- Batch code of the relay
- Z 10003
- Week/year of manufacture of the relay (KW)
- G 03/13
- Manufacturer of the auxiliary relay visible on the PCB
- OMRON
- Omron auxiliary relay
- 24V DC, model prefix G5
Frequently asked questions about the PCB 8748300923
Is this PCB compatible with my Junkers ZWBC 25-2 C 23 C boiler?
Which models are compatible with the Junkers ZWBC 25-2 C 23 C PCB?
What fault code can occur with this PCB?
Is the reference for this PCB PLBO164?
Can I use this PCB in a boiler from the ZWB series?
How many models are compatible with this PCB?
Spare parts related to Bosch Junkers Cerapur Comfort ZWBC (2C)
