Saunier Duval Thematek F 24 E BT 3-Way Valve
The Saunier Duval Thematek F 24 E BT three-way valve, with reference S1020500, switches the water between the heating circuit and the domestic hot water circuit. When it fails, you will notice that there is hot water but no heating, or vice versa, and there may even be a mixing of both circuits. It is compatible with several boilers from the brand, including those from the Thematek series. Replacement should be carried out when you observe these symptoms, as a malfunction can affect comfort in the home.
VAT included
Consult via WhatsAppHow to check if it 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 —. If it is not visible, do not identify the part by 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 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
When opening a hot water tap, the radiators remain cold or take a long time to heat up.
Cause: The valve does not fully switch to the domestic hot water circuit and continues to prioritize heating.
Check if the motor or head of the gas valve moves when requesting hot water; if it does not move, it could be the actuator and not the body of the valve.
- 02
The boiler heats the radiators even if you have only requested hot water.
Cause: The internal shutter of the valve gets stuck halfway and allows water to flow through both circuits simultaneously.
Disassemble the valve and check if the stem moves freely by hand, without any jams.
- 03
Water is leaking from the body of the gas valve or underneath the boiler.
Cause: The internal O-rings wear out over time and lose their sealing capability.
Dry the area and check again after a heating cycle to locate the exact point of the leak before replacing the entire gas valve.
- 04
A click or buzzing sound is heard when turning on the boiler, but the heating or hot water does not work.
Cause: The gas valve motor tries to turn, but the internal mechanism is stuck and does not transmit the movement.
With the boiler turned off, try to turn the shaft of the gas valve by hand to rule out that it is blocked by scale or dirt.
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
- 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
- The body has two embossed marks (diamond and triangle shapes) without any text identifying them.
Frequently asked questions about the 3-way valve
Does this 3-way valve have any readable code or reference?
Spare parts related to Saunier Duval
