Saunier Duval Domestic Hot Water (DHW) Safety Valve 10 Bar Metallic 10BAR Isofast 21 Condens Ref. S5741900
The Safety Valve ACS 10 Bar Saunier Duval Metal 10BAR Isofast 21 Condens Ref. S5741900 is a component that regulates the pressure of the water circuit. Its main function is to release water when the pressure exceeds the usual limit of 3 bar, thus preventing possible damage to the boiler. If this valve fails, you will notice continuous dripping or that it does not discharge when it should. It is compatible with models from the Isomax range, such as the Isomax F28E, and Isotwin, such as the Isotwin C24E, among others. It should be replaced when it shows leaks or does not function properly.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S5741900
Safety valve with reference S5741900. Two confirmed compatibilities: Isomax F28E and Isotwin C24E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Isomax F28E | Isomax | Contrasted |
| Saunier Duval Isotwin C24E | Isotwin | 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. S5741900 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 S5741900. 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 safety valve S5741900 resolves
The safety valve releases pressure when the circuit exceeds its setting. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The valve bleeds water as soon as the boiler starts heating, even though the pressure is within the normal range when cold.
Cause: If the expansion vessel does not properly absorb the expansion of the water, the pressure rises quickly when heating and the valve reacts prematurely.
Measure the pre-charge of the expansion vessel with the system cold and depressurized before changing the gas valve.
- 02
After operating the bleed lever to test it, it keeps dripping and doesn't fully close.
Cause: When opening it manually, a dirt particle can get trapped in the seat, preventing a tight seal.
Open and close the lever several times carefully to try to dislodge the particle before considering it broken.
- 03
White or lime residues can be seen around the valve and on the nearby floor.
Cause: They are marks from previous drips that have already dried, indicating that the valve has not been closing properly for some time.
Check if those stains coincide with the times when the boiler heats more, before assuming that the gas valve is broken.
- 04
The pressure gauge rises more than expected just before the valve discharges water.
Cause: It is the normal reaction of the valve when the circuit pressure exceeds its set point, regardless of the cause of that increase.
Record the cold pressure with the boiler's pressure gauge before touching the valve, to determine if the problem existed beforehand.
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 S5741900 safety valve.
- Catalogue reference
- S5741900
- Brand
- Saunier Duval
- Type of part
- Safety valves
- Units in stock
- 2 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval Isotwin C24E Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the safety valve S5741900
Does this valve fit my Saunier Duval Isomax F28E boiler?
Is this valve suitable for a Saunier Duval Isotwin C24E?
What pressure does this safety valve withstand?
What is the reference for this gas valve?
Are there any fault codes associated with this gas valve?
How many models are compatible with this gas valve?
Spare parts related to Saunier Duval Isomax
