3-Way Valve Saunier Duval Combitek F 23 Ref. 05740400
In the Combitek range boilers, the Saunier Duval Combitek F 23 3-Way Valve Ref. 05740400 is a component that allows the alternation of water flow between the heating circuit and the domestic hot water circuit. If this valve fails, you will notice that you have hot water but no heating, or vice versa, or even that both circuits are mixing. It is installed in models such as the Combitek C 23 and the Combitek F 23, among others. It is advisable to replace it when you experience these water distribution issues.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference 05740400
Three-way valve with reference 05740400. Seven confirmed compatibilities: Thema F 23 E and Thema C 23 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Thema F 23 E | Thema | Contrasted |
| Saunier Duval Thema C 23 E | Thema | Contrasted |
| Saunier Duval Thema 23 | Thema | Contrasted |
| Saunier Duval Themaplus C 23 E | Themaplus | Contrasted |
| Saunier Duval Themaplus F 23 E | Themaplus | Contrasted |
| Saunier Duval Combitek C 23 | Combitek | Contrasted |
| Saunier Duval Combitek F 23 | Combitek | 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. 05740400 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 05740400. 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 3-way valve 05740400 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
There is no hot water but there is heating, or vice versa, when they should work separately without any issues.
Cause: The valve actuator does not move the switch to the correct position and the water does not go to the appropriate circuit.
When requesting hot water, check if you can hear or see the actuator moving; if it doesn't move, the fault points to the gas valve.
- 02
There is a water leak in the area where the 3-way valve is installed.
Cause: The brass body seals lose tightness over time or due to limescale deposits on the internal seat.
Dry the area well and locate the exact point of the leak with the boiler running before declaring the valve as broken.
- 03
A strange noise or effort is heard when the boiler switches between heating and domestic hot water.
Cause: The actuator forces the rotation against a mechanism jammed by scale or by internal wear of the switch.
With the boiler turned off, try to move the actuator by hand and check if it moves easily or is stuck.
- 04
The heating drops in temperature every time a hot water tap is opened.
Cause: The valve does not fully close one circuit while opening the other, mixing cold return water with hot water.
Check if the drop always coincides with the demand for domestic hot water; if so, point to the valve switch.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.318 | The 3-way motorised valve is not moving. | The 3-way valve (actuator or gears) is blocked or without power, so it does not switch between DHW/heating; check by activating the service test and checking voltage/continuity at the motor connector. |
| F.326 | The hydraulic test of the sensor and the actuator has determined that at least two hydraulic components are not functioning. | If the 3-way valve is blocked or disconnected, the hydraulic test detects multiple faults; check the valve movement from the test menu and inspect the connector/wiring harness or replace the assembly if it does not operate. |
| F.081 | The boost has failed. | The brand documents the 3-way valve as a possible cause when it is defective or blocked; confirm by actuating it in service test and, if it does not switch or consumes without turning, replace the valve/motor and check the wiring. |
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 05740400 three-way valve.
- Catalogue reference
- 05740400
- Brand
- Saunier Duval
- Type of part
- 3-way valves
- Units in stock
- 5 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.
- Body
- Brass
- Actuator
- Aluminum
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval Thema F 23 E Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the 3-way valve 05740400
What material is the 3-way valve of the Combitek F 23 made of?
Is this valve suitable for a Saunier Duval Thema C 23 E?
What fault indicates that the 3-way valve of the Combitek needs to be replaced?
Spare parts related to Saunier Duval Thema
