SIT Gas Valve Ariston Ref. 999089
When you turn on the heating, the SIT Ariston gas valve Ref. 999089 is responsible for regulating the flow of gas to the burner according to the instructions from the PCB. If this valve fails, you will notice that the boiler does not ignite, you will experience flame lockouts, or poor modulation. It is compatible with boilers from the Alpha, Eurocombi, and Genus ranges, such as the 23 MFFI and 27 MFFI models, among others. It is recommended to replace it in case the fault code A01 appears, which indicates an ignition failure.
VAT included
Consult via WhatsAppAriston boilers compatible with reference 999089
Gas valve with reference 999089. Seven confirmed compatibilities: 23 MFFI and A23 MFFI.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Ariston 23 MFFI | Alpha | Contrasted |
| Ariston A23 MFFI | Eurocombi | Contrasted |
| Ariston A27 MFFI | Eurocombi | Contrasted |
| Ariston 23 MFFI | Genus | Contrasted |
| Ariston 27 MFFI | Genus | Contrasted |
| Ariston 27 RFFI | Genus | Contrasted |
| Ariston 30 MFFI | Genus | 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. 999089 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 999089. 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 gas valve 999089 resolves.
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 heating is inconsistent: it heats strongly and then suddenly drops, without staying stable.
Cause: The modulation regulator of the gas valve does not properly adjust the gas flow to the power requested by the boiler.
Check if the fault also appears in domestic hot water, to rule out that it is an issue with the sensor or the thermostat.
- 02
The flame appears yellow, unstable, or makes an irregular blowing sound in the burner.
Cause: The gas valve allows an incorrect gas flow, and the mixture with the air is no longer adequate.
Check the condition of the burner and the fan before replacing the gas valve, as poor combustion can also originate from there.
- 03
The boiler never reduces power; it always operates as if it's at full capacity.
Cause: The modulator of the gas valve is stuck in the fully open position.
Check if the fault persists with low heat demand, to confirm that the gas valve does not restrict the gas flow.
- 04
The boiler shuts off by itself during operation and then restarts.
Cause: The gas valve intermittently loses outlet pressure, and the flame goes out halfway through the cycle.
Check the electrical connections of the valve and the control unit before replacing the part.
- 05
When turning on, a small knock or popping sound is heard in the burner.
Cause: The gas valve takes a bit longer to open, and gas accumulates before the spark ignites.
Ensure that the ignition electrode is properly positioned and clean; poor ignition can also cause that knocking sound.
Fault codes for Ariston that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| A01 | Ignition fault: the burner does not ignite within the safety time. | SIT 845 gas valve (ref. 999089) that does not open/flow despite receiving a command from the PCB, causing absence of flame. Check during the ignition attempt that the valve receives voltage and that the coils have continuity; if there is a command and no gas/flame, the valve is faulty. |
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 999089
- Catalogue reference
- 999089
- Brand
- Ariston
- Type of part
- Gas valves
- Units in stock
- 5 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Frequently asked questions about the gas valve 999089
Does reference 999089 have a more recent equivalent in the Ariston catalog?
Is this valve suitable for an Ariston Genus 27 RFFI?
What reliability does the identification of the manufacturer of this part with reference 999089 have?
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