Hydraulic Body 3-Way Valve Without Motor - Isofast Condens F 30 E - Ref. S1025500
If you notice that you have hot water but no heating, or that both circuits are mixing, you may need the Hydraulic body 3-way valve without motor - Isofast Condens F 30 E - Ref. S1025500. This valve is responsible for directing water between the heating circuit and the domestic hot water circuit. When it fails, it can generate the fault code F.20: Safety disconnection: temperature limiter. It is compatible with several boilers from the Isofast, Isomax, Isotwin, and Themafast ranges, among others. It is recommended to replace it when these symptoms are present to restore proper operation.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S1025500
3-way valve with reference S1025500. 18 verified compatibilities: F 35 E-A and F 30 E-A.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F 35 E-A | Isofast | Contrasted |
| Saunier Duval F 30 E-A | Isofast | Contrasted |
| Saunier Duval C 35 E-A | Isofast | Contrasted |
| Saunier Duval F 35 E H-MOD | Isofast | Contrasted |
| Saunier Duval F 30 E H-MOD | Isofast | Contrasted |
| Saunier Duval Condens F 30 E | Isofast | Contrasted |
| Saunier Duval Condens F 35 E | Isofast | Contrasted |
| Saunier Duval F 35 E | Isomax | Contrasted |
| Saunier Duval F 35 H-MOD | Isomax | Contrasted |
| Saunier Duval Condens F 35 E | Isomax | Contrasted |
| Saunier Duval F 30 H-MOD | Isotwin | Contrasted |
| Saunier Duval Condens F 30 E | Isotwin | Contrasted |
| Saunier Duval F 25 E | Themafast | Contrasted |
| Saunier Duval F 30 E | Themafast | Contrasted |
| Saunier Duval C 25 E | Themafast | Contrasted |
| Saunier Duval C 30 E | Themafast | Contrasted |
| Saunier Duval Condens F 25 | Themafast | Contrasted |
| Saunier Duval Condens F 30 | Themafast | 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. S1025500 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 S1025500. 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 S1025500 three-way valve resolves.
The 3-way valve diverts water between heating and domestic hot water. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
Water is leaking from the body of the valve even though the motor and the electrical switch are functioning normally.
Cause: The seals or the seat of the shutter in the hydraulic body are worn or cracked.
Confirm that the leak is coming from the body itself and not from a nearby connection joint before replacing it.
- 02
The motor completes its full cycle, but the water continues mixing heating and domestic hot water.
Cause: The internal shutter is broken, misaligned, or covered in scale, and it does not seal even though the motor is functioning properly.
With the boiler cold, disassemble the motor and manually check if the shutter moves freely and seals in both positions.
- 03
The flow rate of heating or domestic hot water has clearly decreased, even though the rest of the installation is fine.
Cause: The internal passage of the hydraulic body is narrowed by limescale or accumulated dirt.
Check the condition of the scale inside the body, especially if the water in the area is hard, before replacing it.
- 04
Water hammer or pipe noise right when switching circuits
Cause: The shutter seat is worn and does not cushion the closure properly.
Check if the knock always occurs at the exact same point during the mode change.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.20 | Safety shutdown: temperature limiter. | If the 3-way valve (priority valve) is blocked or disconnected, the primary flow does not switch correctly and the generator overheats, triggering the F.20; to verify, force the test/diagnosis that moves the valve from the service menu and check the power supply/wiring and ensure the shaft/motor are not seized. |
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 3-way valve S1025500.
- Catalogue reference
- S1025500
- Brand
- Saunier Duval
- Type of part
- 3-way valves
- Units in stock
- 1 unit
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Frequently asked questions about the 3-way valve S1025500
Is this hydraulic body three-way valve without motor – Isofast Condens F 30 E – Ref. S1025500 compatible with my boiler Isofast F 30 E-A?
Does this hydraulic body work for the Isomax range?
Can I use this hydraulic body in my Isotwin F 30 H-MOD boiler?
What is the reference for this hydraulic body?
What fault codes are documented for this product?
How many models are compatible with this hydraulic body?
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