Honeywell PCB Junkers Bosch Euroline ZW23-1AE23
If your boiler does not start or behaves erratically, the Honeywell Junkers Bosch Euroline ZW23-1AE23 PCB may be the solution. This control board regulates the ignition, burner modulation, pump, and safety features of the boiler. When it malfunctions, you may notice that the reset button blinks at 0.5 Hz or 4 Hz, indicating problems with ignition or the circuit. It is compatible with several models from the Junkers Euroline range, such as the ZW23-1AE23 and the ZS23-1AE23, among others. It is recommended to replace it when the boiler shows these symptoms of malfunction.
VAT included
Consult via WhatsAppBosch Junkers boilers compatible with reference 87083002120
PCB with reference 87083002120. 22 verified compatibilities: ZW23-1AE23 and ZW23-1AE31.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Bosch Junkers ZW23-1AE23 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW23-1AE31 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW23-1KE23 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW23-1KE31 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW24-1ELH AE23 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW24-1ELH AE31 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW28-1LHKE23 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW28-1LHKE31 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW30-1LHAE23 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZW30-1LHAE31 | Junkers Euroline ZW (combi) | Contrasted |
| Bosch Junkers ZS23-1AE23 | Junkers Euroline ZS (heating only) | Contrasted |
| Bosch Junkers ZS23-1AE31 | Junkers Euroline ZS (heating only) | Contrasted |
| Bosch Junkers ZS23-1KE23 | Junkers Euroline ZS (heating only) | Contrasted |
| Bosch Junkers ZS23-1KE31 | Junkers Euroline ZS (heating only) | Contrasted |
| Bosch Junkers NW24-1LHAE23 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24-1LHAE31 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24-1LHKE23 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24-1LHKE31 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24/28-1LHKE23 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24/28-1LHKE31 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24/30-1LHAE23 | Junkers Euroline NW24 | Contrasted |
| Bosch Junkers NW24/30-1LHAE31 | Junkers Euroline NW24 | 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. 87083002120 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 87083002120. If it is not visible, do not identify the part by 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 87083002120 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 respond to any button on the panel.
Cause: It is not receiving power from the PCB, so no controls or indicators are functioning.
Check the fuse and the power supply before deciding that the PCB is the culprit.
- 02
The burner ignites but the boiler shuts down immediately and shows a lockout.
Cause: The PCB detects an incorrect safety signal and stops the cycle even though the combustion is correct.
Check the flame detection electrode and its connection before replacing the PCB.
- 03
The indicators are flashing in a pattern that does not appear in the manual.
Cause: The microprocessor on the PCB is damaged, so the indicators do not correspond to a real fault code.
Perform a full reset by cutting the power for one minute; if the pattern doesn't change, the fault is likely in the PCB.
- 04
The boiler modulates poorly or stays fixed at maximum power.
Cause: The PCB regulates the modulation of the flame according to the demand; if it fails, it loses that management.
Check the outdoor or flow temperature sensor, if installed, before assuming the PCB is responsible.
Fault codes for Bosch Junkers that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| Reset button flashing 0.5 Hz + LED 75 °C | During ignition: ionisation signal is detected but the burner does not ignite. | The printed circuit board (PCB 87083002120) may fail in the detection/ionisation path or be damp, causing false flame or lack of spark; check ionisation microamperage, wiring, and moisture/oxidation on the PCB before replacing it. |
| Reset button flashes at 4 Hz (four times per second) | Control/safety fault (encoder/sensors) including possible PCB defect. | Fault in the PCB (Eurotronic/PCB) in managing inputs/power supplies; check voltages at ST2 (L–N/LR–N), fuses F1/F2, and 5 V to sensors. If everything is correct and the symptom persists, replace the 87083002120. |
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 87083002120
- Catalogue reference
- 87083002120
- 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.
- Manufacturer marked on the part
- Honeywell
- Marking of the relay/transformer plastic casing
- 94V-0
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Bosch Junkers ZW23-1KE23 manual (PDF)Document © Bosch Junkers, provided as a technical reference.
Frequently asked questions about the PCB 87083002120
Is this PCB compatible with my Junkers Bosch Euroline ZS23-1KE31 boiler?
Is it an original Junkers or Bosch PCB for the Euroline ZW24-1 ELH AE31?
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