SIT 845 Sigma Gas Valve for Ariston AS 24 FF - Ref. 65104254
In the Ariston AS 24 FF boilers, the SIT 845 Sigma Gas Valve - Ref. 65104254 regulates the flow of gas to the burner according to the commands from the PCB. If this valve fails, you may notice that the boiler does not ignite, experience flame lockouts, or that the flame does not modulate correctly, which can lead to faults such as 5 02, 5 01, or 5 04. This valve is compatible with other models from the AS, BS, Clas, Egis, Genus, and Matis ranges, among others. A technician must confirm through diagnosis whether it is necessary to replace it when these symptoms are detected or in the case of an evident malfunction.
- Type of part
- Gas valves
- Status
- Refurbished
- Catalogue reference
- 65104254
- Warranty
- 1 year
Ariston boilers compatible with reference 65104254
Gas valve with reference 65104254. Ten verified compatibilities: AS 24 FF and BS 24 FF.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Ariston AS 24 FF | AS / BS / BS II | Contrasted |
| Ariston BS 24 FF | AS / BS / BS II | Contrasted |
| Ariston BS II 24 FF | AS / BS / BS II | Contrasted |
| Ariston Clas 24 FF | Clas / Clas Evo | Contrasted |
| Ariston Clas Evo 24 FF | Clas / Clas Evo | Contrasted |
| Ariston Egis 24 FF | Egis / Egis Plus | Contrasted |
| Ariston Egis Plus 24 FF | Egis / Egis Plus | Contrasted |
| Ariston Genus 24 FF | Genus / Genus Evo | Contrasted |
| Ariston Genus Evo 24 FF | Genus / Genus Evo | Contrasted |
| Ariston Matis 24 FF | Matis | 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. 65104254 is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 65104254. 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 that require diagnosis in the gas valve 65104254
The gas valve regulates and modulates the gas flow to the burner. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The boiler tries to ignite but locks out as soon as it starts, before the flame comes out.
Cause: The solenoid of the gas valve does not open the gas flow in time, and the control board cuts off the ignition for safety.
Measure if there is current to the electromagnet at the moment of ignition (multimeter on the connector) before declaring it faulty.
- 02
After the boiler shuts down, there is still a noticeable smell of gas near the burner.
Cause: The electromagnet does not close properly and allows some gas to pass through even though the flame has already gone out.
Ventilate the area and visually check that the solenoid fits properly and that the closing spring is not broken or dislodged.
- 03
The flame rises and falls on its own, or it makes noises when changing power.
Cause: The modulating part of the gas valve does not regulate the gas flow properly according to the burner demand.
Check that the incoming gas filter is not dirty and that the network pressure is normal before attributing it to the gas valve.
- 04
You smell gas near the boiler even when it is turned off.
Cause: There may be a leak in the joints or in the body of the gas valve, a known wear point in this SIT 845 series.
Shut off the shut-off valve and locate the leak with leak detection spray before touching anything; do not confirm it just by smell.
Ariston fault codes that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| 5 02 | Flame detected with the gas valve closed. | The gas valve remains open or leaks when the PCB commands it to close, so the ionisation continues to detect a flame. Check for a flame signal without voltage on the valve and verify closure/sealing and pressures of the ramp according to the manufacturer's table. |
| 5 01 | Flame not detected during ignition (ignition lockout). | The gas valve does not open or delivers insufficient flow during start-up. Check for voltage presence in coils during the attempt, outlet/offset pressure according to the manual, and if there is voltage without gas flow, replace or adjust the valve. |
| 5 04 | Flame lift-off during operation. | Unstable regulation or modulation of the gas valve causes an unstable flame. Check and adjust the offset and minimum/maximum flow rates of the valve according to the table and perform a combustion analysis to stabilise the mixture. |
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 Ariston gas valve 65104254
- Catalogue reference
- 65104254
- Uniclima internal SKU
- VGCAAS24FF
- Brand
- Ariston
- Type of part
- Gas valves
- Units in stock
- 6 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- Manufacturer
- SIT
- Product line
- 845 Sigma
- Country of manufacture
- Italy (Padua)
- Electromagnet marking (blue part)
- 8G19
Frequently asked questions about the gas valve 65104254
Is the SIT 845 Sigma gas valve compatible with my Ariston AS 24 FF?
Is it an original Ariston part?
When should I change the gas valve in my Ariston Clas 24 FF?
Where is the SIT 845 Sigma gas valve manufactured?
What fault codes are related to this gas valve?
What is the reference for this gas valve?
Spare parts related to Ariston AS / BS / BS II
