SIT 845 Sigma Gas Valve - Fagor FE20E / FE20E1N - Ref. MU0809100
SIT gas valve model 845 Sigma, manufactured in Italy (Padova). It combines two solenoid valves (EV1 and EV2) and a modulator to regulate the gas flow to the burner and adjust the flame. Maximum inlet pressure is 60 mbar and outlet pressure ranges between 1 and 37 mbar. It is sold with the catalog reference MU0809100.
VAT included
Consult via WhatsAppFagor boilers compatible with reference MU0809100
Gas valve with reference MU0809100. 12 verified compatibilities: FE-20E/2N and FE-20E/2B.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Fagor FE-20E/2N | Fagor Eco Compact FE-20E | Contrasted |
| Fagor FE-20E/2B | Fagor Eco Compact FE-20E | Contrasted |
| Fagor FE-20E | Fagor Eco Compact FE-20E | Contrasted |
| Fagor FE-24E | Fagor FE (rest of series) | Contrasted |
| Fagor FE-27E | Fagor FE (rest of series) | Contrasted |
| Fagor FE-24NOX | Fagor FE (rest of series) | Contrasted |
| Fagor FA-20E2N | Fagor FA | Contrasted |
| Fagor FA-23EN | Fagor FA | Contrasted |
| Fagor FEB-20E | Fagor FEB | Contrasted |
| Fagor FEE-20 | Fagor FEE | Contrasted |
| Fagor CA-20EN | Fagor CA | Contrasted |
| Fagor CE-20E | Fagor CE | 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. MU0809100 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 MU0809100. 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 MU0809100 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 boiler tries to start but does not ignite the flame.
Cause: The EV1 solenoid valve of the SIT valve does not open the gas supply for ignition.
Check that there is a spark at the electrode and that the gas is arriving with normal pressure before replacing the gas valve.
- 02
The flame ignites but does not increase in power no matter how much you raise the temperature.
Cause: The solenoid valve EV2 or the modulator MD do not allow increasing the gas flow.
Check that the modulation signal from the PCB reaches the gas valve connector.
- 03
The flame flickers or an irregular crackling sound is heard from the burner.
Cause: The modulator does not maintain a stable gas flow to the burner.
Measure the gas inlet pressure with a manometer before replacing the modulator.
- 04
Notes a smell of gas or moisture residue on the gas valve casing.
Cause: Loss of internal tightness in the SIT valve
Apply leak detection spray on joints and fittings, with the gas turned off if the indication is clear.
Fault codes for Fagor that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F1 | Lockout due to ignition fault (flame not established). | The faulty/stuck gas valve may not open or modulate at startup, and insufficient gas may reach for ionization; check voltage in coils during the ignition attempt and pressure/flow in the ramp, ensuring the valve opens. |
| F6 | Flame detection with the burner at rest (parasitic flame). | If the gas valve does not close hermetically, it allows gas to pass and a residual flame persists; check the valve's closure/sealing when stopped and rule out a false ionization signal. |
| F10 | Fault in the control or closure of the gas valve. | Fault in the valve or its control circuit (coils/relays) prevents proper opening/closing; check coil continuity, control voltage from the PCB, and ensure the flame extinguishes when closure is commanded. |
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 gas valve Fagor MU0809100
- Catalogue reference
- MU0809100
- Brand
- Fagor
- Type of part
- Gas valves
- Units in stock
- 5 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Data read on the part and in the manufacturer's documentation
What we have not been able to verify does not appear here.
- Manufacturer (engraved on label)
- SIT
- Model
- 845 SIGMA
- Component code
- 0063AS4831
- Inlet pressure (Pi max)
- 60 mbar
- Outlet pressure (Po)
- 1-37 mbar
- EV1
- 230V~50Hz, 9.2 VA class B
- EV2
- 230V~50Hz, 2.8 VA class J
- Modulator (MD)
- MAX 17V DC
- Maximum consumption
- 165 mA
- Ambient temperature
- 0/60°C
- Type of gas (according to label)
- ALLGAS
Frequently asked questions about the gas valve MU0809100
Who manufactures the SIT 845 Sigma gas valve used in the Fagor FE20E?
Does this SIT 845 Sigma valve also work for a Fagor FE20E1N?
Is the reference MU0809100 from the manufacturer SIT or from Fagor?
What outlet pressure does the valve of the Fagor FE20E regulate?
What is the function of the solenoid valves of the SIT 845 Sigma valve in the Fagor FE20E1N?
Spare parts related to Fagor Eco Compact FE-20E
