Junkers PCB ZWBC 25-2 C 23 Cerapurcomfort - Ref. 8748300923

Junkers boilers compatible with reference 8748300923

PCB with reference 8748300923. Four confirmed compatibilities: ZWBC 24-2C and ZWBC 25-2C.

Proven compatibility

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

The part reference, model, and equipment revision must be verified against the manufacturer's documentation.

1. 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.
2. Check the full boiler model on its data plate and look for it in the model associations on this page.
3. Compare the connections and physical body with the original part before installation.
4. If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.

Symptoms that require diagnosis on the PCB 8748300923

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.

Junkers fault codes that require diagnosis

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 Junkers 8748300923 PCB.

Catalogue reference

8748300923

Uniclima internal SKU

PLBO164

Brand

Junkers

Type of part

PCBs (control boards)

Units in stock

1 unit

Status

Refurbished

Warranty

1 year

Shipping

Delivery time shown at checkout

Return

14 days

Part data and available documentation

Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.

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