3-Way Valve Saunier Duval Themafast F 24 E Ref. S1020900
Refurbished Saunier Duval 3-way valves

3-Way Valve Saunier Duval Themafast F 24 E Ref. S1020900

The 3-way valve Saunier Duval Themafast F 24 E (Ref. S1020900) is a component that regulates the flow of water between the heating circuit and the domestic hot water circuit. If it malfunctions, you will notice that there is hot water but no heating, or vice versa, and there may even be a mixing of both circuits. This valve is compatible with several models from the Themafast range, including the Themafast C 24 E, C 28 E, and F 30 E, among others. A technician must confirm through diagnosis whether it needs to be replaced when the mentioned symptoms are detected or if the fault code F14 is activated, which indicates an overheating in the heating supply.

Type of part
3-way valves
Status
Refurbished
Catalogue reference
S1020900
Warranty
1 year
VAT included Stock · 1 unit
Compatibility

Saunier Duval boilers compatible with reference S1020900

Three-way valve with reference S1020900. Six confirmed compatibilities: Themafast C 24 E and Themafast C 24 E NOX.

Verified compatibility

Boiler modelFamilyVerification
Saunier Duval Themafast C 24 EThemafastVerified
Saunier Duval Themafast C 24 E NOxThemafastVerified
Saunier Duval Themafast C 28 EThemafastVerified
Saunier Duval Themafast F 24 EThemafastVerified
Saunier Duval Themafast F 24 E NOxThemafastVerified
Saunier Duval Themafast F 30 EThemafastVerified

Can't see your model or have questions? The printed reference takes precedence. How to check it ·

Guide

How to check if ref. S1020900 is the part for your boiler

The part reference, model, and equipment revision must be verified against the manufacturer's documentation.

  1. Find the reference printed on the installed part and check whether it matches the catalogue reference S1020900. If it is not visible, do not identify the part from its shape alone.
  2. Check the full boiler model on its data plate and look for it in the model associations on this page.
  3. Compare the connections and physical body with the original part before installation.
  4. If anything is unclear, send us a photo of the marking via WhatsApp before placing your order.
Diagnosis and fault codes

Symptoms that require diagnosis in the 3-way valve S1020900

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

    The radiators heat up when you only request hot water from the tap.

    Cause: The three-way valve does not completely close the passage to heating and allows water to pass through both circuits simultaneously.

    With the boiler cold, check if the valve shaft moves freely between the two positions or if it is stuck.

  • 02

    The domestic hot water takes a long time to come out hot or comes out lukewarm.

    Cause: The valve does not fully switch to the domestic hot water circuit and gets stuck halfway.

    Listen to see if the valve motor makes the switching click when a tap is opened; if you don't hear it, the suspicion points here.

  • 03

    The heating is not warming up even though the boiler ignites and modulates well.

    Cause: The valve gets stuck in the domestic hot water position and does not divert water to the heating circuit.

    Check for leaks or drips around the valve body, a typical sign that the internal seat is no longer sealing.

  • 04

    A buzzing or knocking sound is heard in the area of the valve when switching between domestic hot water and heating.

    Cause: The motor forces the position change because the internal mechanism resists.

    Check for any limescale or dirt blocking the stem's path before replacing the complete gas valve.

Fault codes Saunier Duval that require diagnosis

CodeFaultTechnical checks
F14Overtemperature in heating flow (>95 °C) – limiter triggered.If the 3-way valve gets stuck in the heating position during a DHW demand, it does not switch the flow to the heat exchanger, and the supply heats up very quickly causing F14; check that the V3V actuator moves and has power, force its travel/remove the actuator to verify passage and confirm that it switches.

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.

Technical data

Data sheet for the Saunier Duval S1020900 three-way valve.

Catalogue reference
S1020900
Uniclima internal SKU
BHCTF24E
Brand
Saunier Duval
Type of part
3-way valves
Units in stock
1 unit
Status
Refurbished
Warranty
1 year
Shipping
Delivery time shown at checkout
Return
14 days
Frequently asked questions

Frequently asked questions about the 3-way valve S1020900

Is this Saunier Duval 3-way valve Ref. S1020900 suitable for the Themafast F 24 E?
Yes, the Themafast F 24 E is on the list of compatible boilers.
Is this gas valve compatible with the Themafast C 24 E?
Yes, the Themafast C 24 E is on the list of compatible boilers.
Does this valve work for the Themafast F 30 E?
Yes, the Themafast F 30 E is on the list of compatible boilers.
What fault codes are documented for this gas valve?
The documented fault code for this gas valve is F14.
How many models are compatible with this gas valve?
This valve is compatible with a total of 6 models from the Themafast range.
What is the reference for this 3-way valve?
BHCTF24E is Uniclima’s internal SKU for locating this listing. To confirm compatibility, check the manufacturer’s reference and the exact appliance model.

Spare parts related to Saunier Duval Themafast

More spare parts for Saunier Duval Themafast F 24 E

Delivery calculated by destination Delivery time shown at checkout
1-year warranty inspected and tested
14-day return uninstalled parts
Technical support we verify your model
3-Way Valve Saunier Duval Themafast F 24 E Ref. S1020900