Long Extension Filling Key Saunier Duval Isofast F 30 E Ref. S10254
Saunier Duval Isofast F 30 E includes the Long Filling Key Extension, which allows you to refill water into the heating circuit to maintain the proper pressure. If this part fails, you will notice that you cannot refill the circuit or that it is continuously leaking water, which can lead to an increase in pressure. It is compatible with models such as the F30 E and F35E, among other boilers in the Isofast range. It is recommended to replace it when you observe filling issues or water leaks.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S10254
Filling key with reference S10254. Two confirmed compatibilities: F30 E and F35E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F30 E | ISOFAST | Contrasted |
| Saunier Duval F35E | ISOFAST | 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 part S10254 is the one 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 S10254. 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 filling valve S10254 resolves.
The filling valve allows water to refill the heating circuit. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler pressure is always high, or it needs to be bled frequently because it rises on its own.
Cause: A filling valve that does not close properly allows mains water to continuously flow in, even when it is in the closed position.
Note the cold pressure one night and compare it to the next morning without touching anything; a clear increase indicates that the valve is not closing properly.
- 02
There is a limescale stain or a constant drip right below the filling valve.
Cause: The constant flow of water through a worn joint leaves a white lime mark, indicating that it no longer seals completely.
Clean the area and check when cold, with the boiler turned off, if the dripping continues even with the tap fully closed.
- 03
The key turns very stiffly or makes a strange noise when opening or closing it.
Cause: In a plastic tap like this, limescale and sediments end up jamming the mechanism before it breaks.
Try moving it several times carefully without forcing it too much; if it remains very stiff or doesn't close completely, it is advisable to replace it.
- 04
When trying to fill the circuit, the pressure does not rise at all or rises very slowly.
Cause: If the internal pipe of the valve is blocked, even if it is open, the water does not flow with sufficient flow rate.
First, check the water shut-off valve of the house or installation: if it is closed or barely open, it will show the same symptom without the filling valve having anything to do with it.
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.
Fiche of the filling key Saunier Duval S10254
- Catalogue reference
- S10254
- Brand
- Saunier Duval
- Type of part
- Filling valves
- Units in stock
- 7 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Frequently asked questions about the filling key S10254
Does this filling valve work only for the Isofast F30 E or also for the F35 E?
What is the difference between this key S10254 and the key SDS10068 from other Saunier Duval data sheets?
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