Saunier Duval Isofast Condens F30 B 1 Circulating Pump Ref. 0020084525
The circulation pump moves water through the heating circuit. This model from Saunier Duval, reference 0020084525, is compatible with boilers from the Isofast, Isomax, and Isotwin ranges, such as the model 21 Condens F 30-B, among others. When the pump fails, you may notice cold radiators, strange noises, overheating, or blockages due to lack of circulation. The associated fault codes are F.23, F.24, and F.75. It is recommended to replace the pump when these symptoms or the mentioned codes occur.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 0020084525
Circulating pump with reference 0020084525. Six confirmed compatibilities: 21 Condens F 30-B and Condens F 30-B.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval 21 Condens F 30-B | Isofast | Contrasted |
| Saunier Duval Condens F 30-B | Isomax | Contrasted |
| Saunier Duval Condens F 35-B | Isomax | Contrasted |
| Saunier Duval Condens F 25/30-B | Isotwin | Contrasted |
| Saunier Duval Condens F 30/35-B | Isotwin | Contrasted |
| Saunier Duval Condens F AS 30 | Thema | 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 the reference 0020084525 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 0020084525. 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 0020084525 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 heating heats little or not at all even though the burner is working.
Cause: The integrated pump with the distribution valves is not moving the water correctly, preventing the heat from reaching.
Check if the valves of the assembly are moving, as they sometimes get stuck before considering that the pump is faulty.
- 02
A strange buzzing or gurgling sound is heard when turning on the heating.
Cause: This is usually caused by air in the pump-valve assembly or by a lack of pressure, not necessarily due to a motor fault.
Bleed the circuit and check the filling pressure before replacing the part.
- 03
There is a water leak around the pump-valve assembly body.
Cause: The plastic gaskets between the pump and the valves can start to leak over time.
Locate the exact point of the leak (pump, valve, or joint) before requesting the complete assembly.
- 04
The pump does not start after stopping the heating in summer.
Cause: The impeller can seize up due to sediment and inactivity, which is common in boilers that only use domestic hot water in the summer.
Try to unlock it manually if the model allows it before purchasing a new set.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.23 | Safety shutdown: excessive temperature variation | A blocked or reduced power pump decreases the flow rate and causes the ΔT flow/return to rise excessively; check that the pump is rotating, its consumption/PWM signal, and bleed the circuit. |
| F.24 | Safety shutdown: temperature rise too fast | If the pump is blocked or underperforming, the power is not evacuated and the primary temperature rises very quickly; check the pump's rotation/electrical consumption, bleed air, and confirm the installation pressure. |
| F.75 | Pump error, lack of water | At start-up, the PCB does not detect the expected pressure increase if the pump does not start or does not generate flow; check the pump's power supply/signal and the pressure increase during the diagnostic test, as well as bleed. |
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 Saunier Duval circulator pump 0020084525
- Catalogue reference
- 0020084525
- Brand
- Saunier Duval
- Type of part
- Pumps
- Units in stock
- 3 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Frequently asked questions about the circulator pump 0020084525
Is this pump suitable for an Isomax Condens F35-B?
Is this pump suitable for a Thema Condens F AS 30?
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