Junkers Circulating Pump ZW231AE23S3705
Circulating pump for Junkers boilers. It circulates the water in the heating circuit between the boiler and the radiators. It operates at 230V and 50Hz, with a 3.5 µF capacitor and a maximum pressure of 0.3 MPa. It is replaced when it fails to start, makes noise, or the heating stops warming due to lack of circulation.
Junkers boilers compatible with reference 8707204042
Circulating pump with reference 8707204042. Ten verified compatibilities: ZW231AE23S3705 and ZW231AE31S3705.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Junkers ZW231AE23S3705 | Junkers Euroline ZW 23-1 AE | Contrasted |
| Junkers ZW231AE31S3705 | Junkers Euroline ZW 23-1 AE | Contrasted |
| Junkers ZW23-1 AE23 | Junkers Euroline ZW 23-1 AE | Contrasted |
| Junkers ZW24AE23S2805 | Junkers Ceraclass ZW 24 AE | Contrasted |
| Junkers ZW24AE31S2805 | Junkers Ceraclass ZW 24 AE | Contrasted |
| Junkers ZW24KE23S2895 | Junkers Ceraclass ZW 24 AE | Contrasted |
| Junkers ZW24-1 AE23 | Junkers Ceraclass ZW 24 AE | Contrasted |
| Junkers NW241ELHAE23S28 | Junkers ZW/ZS 24-1 (NW241/ZS231) | Contrasted |
| Junkers ZW241ELHAE23S28 | Junkers ZW/ZS 24-1 (NW241/ZS231) | Contrasted |
| Junkers ZS231AE23S3705 | Junkers ZW/ZS 24-1 (NW241/ZS231) | 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. 8707204042 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 8707204042. 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 circulation pump 8707204042 resolves.
The circulation pump circulates the water in the heating circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The pump is buzzing but does not spin when the heating requests heat.
Cause: A degraded capacitor prevents the motor from starting even though it receives power.
If you feel that the body vibrates but does not rotate, try to unlock the shaft by hand; if it rotates without resistance, suspect the capacitor before replacing the pump.
- 02
The heating is not working well even though the boiler ignites, as if the water is not circulating.
Cause: Without sufficient circulation, hot water does not reach the radiators even though the burner operates normally.
Check that the radiators heat evenly and that there is no air in the circuit before declaring the pump faulty.
- 03
There is noticeable noise or vibration in the pump during operation.
Cause: It may be due to air in the circuit or scale buildup in the impeller, not always related to the motor.
Bleed the circuit and the pump before replacing it.
- 04
After stopping the heating in summer, the pump gets stuck when restarting.
Cause: The shaft seizes due to inactivity and sediment buildup, which is common in pumps that have not been running for months.
Try to manually release the shaft with a flat screwdriver in the front slot before purchasing the spare part.
Fault codes from Junkers that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| The reset button flashes 2 times per second (2 Hz), and the 45 °C indicator light also flashes. | The temperature limiter sensor has detected an overheating. | A seized/faulty circulating pump prevents the circulation of the primary, the flow temperature rises, and the limiter activates. Check by unlocking the shaft from the front screw of the pump and verifying that there is circulation and electrical consumption of the pump. |
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 circulator pump Junkers 8707204042
- Catalogue reference
- 8707204042
- Brand
- Junkers
- Type of part
- Pumps
- 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.
- Voltage
- 230V~
- Frequency
- 50 Hz
- Condenser
- 3.5 µF
- Protection
- IP44, Class H, TF95
- Maximum pressure
- Max. 0.3 MPa
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Junkers Euroline ZW 23-1 AE ZW231AE23S3705 manual (PDF)Document © Junkers, provided as a technical reference.
Frequently asked questions about the circulator pump 8707204042
What voltage and frequency does the pump with Ref. 8707204042 operate at?
What fault indicates that the pump of a Junkers ZW231AE23S3705 boiler needs to be replaced?
Does this pump work for a Junkers ZW24AE23S2805 boiler?
What capacitor does the pump of the ZW231AE23S3705 use?
What is the maximum pressure this pump can withstand?
Spare parts related to Junkers Ceraclass ZW 24 AE
