Junkers Eurosmart ZWA24-1AM23 PCB Ref. 8748300417
The Junkers Eurosmart ZWA24-1AM23 Electronic Control Board, Ref. 8748300417, is a component that controls the ignition, burner modulation, pump, and safety features of the boiler. When it fails, the boiler may not start, become locked, or exhibit erratic operation. Symptoms include the reset button flashing at 1 Hz, indicating ignition or overheating issues, at 4 Hz, related to flue gas evacuation failures, or at 8 Hz, pointing to problems with the operation mode switch. This board is compatible with models from the Junkers Eurosmart ZWA 24 range, such as ZWA 24-1A23 and ZWA 24-1A31, among others. It is recommended to replace it when the mentioned symptoms occur.
Junkers boilers compatible with reference 8748300417
PCB with reference 8748300417. Four confirmed compatibilities: ZWA 24-1A23 and ZWA 24-1A31.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Junkers ZWA 24-1A23 | Junkers Eurosmart ZWA 24 | Contrasted |
| Junkers ZWA 24-1A31 | Junkers Eurosmart ZWA 24 | Contrasted |
| Junkers ZWA 24-1K23 | Junkers Eurosmart ZWA 24 | Contrasted |
| Junkers ZWA 24-1K31 | Junkers Eurosmart ZWA 24 | 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. 8748300417 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 8748300417. 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 8748300417 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
The boiler does not start or show any sign of life when the switch is pressed.
Cause: The PCB distributes power and gives the ignition command to the entire unit; if it fails, there is no reaction of any kind.
Check that power is reaching the input of the PCB and that the internal fuse is not blown before replacing it.
- 02
A fault code appears that requires resetting the boiler several times a day.
Cause: Repeated resets with the same code usually indicate that the PCB is incorrectly detecting a safety condition and interrupts the process each time.
Write down the exact code and compare it with the Junkers list for this series; some codes refer to the sensor or the pressure switch, not the PCB.
- 03
The boiler works for domestic hot water but not for heating, or vice versa.
Cause: The PCB manages both circuits separately; a fault in the part that controls one of the modes may leave the other functioning normally.
Confirm the exact mode in which it fails and ensure that the boiler selector is correctly set before considering the PCB.
- 04
The boiler loses its programming or the time every time there is a power outage.
Cause: This may be due to a fault in the backup battery or in the memory of the motherboard itself.
First, check if the PCB has an accessible backup battery and what condition it is in before considering the electronics as faulty.
Fault codes from Junkers that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| The reset button flashes at 1 Hz (once per second) | 1 Hz light code that groups ignition/overheating/internal fault. | The PCB (Eurotronic printed circuit board) may fail in ignition management or signal reading and cause this pattern; check with Test D in the manual (voltages at ST2 L–N, spark/ionisation, and wiring) and, if everything else is correct, replace the PCB. |
| The reset button flashes at 4 Hz (four times per second) | 4 Hz light code for evacuation supervision/safety and sensors (pressure switch, fan, NTC, encoder connector). | A defect in the PCB can prevent correct reading of the pressure switch/NTC/fan or managing the flue safety, generating the 4 Hz; check with Test E (pressure switch pressures, fan, continuity/wiring, and 230 V/5 V at connectors) and, if everything is fine, the PCB is faulty. |
| The reset button flashes at 8 Hz (eight times per second) | 8 Hz light code associated with the operation mode switch (Min/Max position) and its circuit. | If the switch line on the board (input/UI or logic) is forced or not interpreted due to a fault in the printed circuit, it maintains the 8 Hz; check the switch itself and its wiring to the PCB, and if there are no external anomalies, replace the board. |
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 8748300417 PCB.
- Catalogue reference
- 8748300417
- Brand
- Junkers
- Type of part
- PCBs (control boards)
- Units in stock
- 0 units
- 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.
- Successor reference Junkers
- 8748300417 (replaces 8748300496, same boiler manufacturer: Junkers)
- The current catalog refers to the model as 'Zwea 24 1AM 23'; the confirmed model is ZWA24-1AM23 (and the variants A23S0407 / K23S0492).
Frequently asked questions about the PCB 8748300417
Is this PCB Ref. 8748300417 suitable for the Junkers Eurosmart ZWA24-1 K23S0492?
Is the reference 8748300417 correct for the Junkers Eurosmart ZWA24-1AM23?
Is this PCB suitable for the Junkers Eurosmart ZWA24-1 A23S0407?
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