SIT 845 SIGMA Gas Valve for Fagor FE20E, FE20E1N, and FEE20 - Code 0063AS4831
SIT gas valve model 845 SIGMA, manufactured in Italy (Padova), manufacturer and specifications also confirmed by external sources. It is installed in Fagor boilers FE20E, FE20E1N, and FEE20. It regulates the gas inlet and outlet with two solenoid valves (EV1 and EV2) and a modulator (MD): maximum inlet 60 mbar, adjustable outlet 1-37 mbar. It is replaced when ignition fails or the flame modulates poorly.
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 ignite but the burner does not light.
Cause: The solenoid valve EV1 does not open the gas flow, so fuel does not reach the burner.
Before replacing it, measure the continuity of the EV1 coil with a multimeter and check that it receives current at the moment of ignition.
- 02
The flame ignites but does not increase in power despite the need for more heat.
Cause: The MD modulator or the EV2 solenoid valve do not open enough to allow for more gas flow.
Make sure that the power limit is not programmed on the PCB or that it is not a problem with the temperature sensor before replacing the gas valve.
- 03
The control panel shows a warning or lock of the gas valve.
Cause: The electronics detect that the gas valve does not respond to the command to open or close and it locks for safety.
Note the exact code on the display: some blockages of this type can be reset and do not always indicate that the gas valve is faulty.
- 04
The flame is unstable, rising and falling without any change in demand.
Cause: The regulation between EV2 and the modulator MD does not maintain a constant gas flow.
Check that the incoming gas filter is not dirty, as this can cause the same symptom without the gas valve failing.
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
- SIT
- Model / family
- 845 SIGMA
- SIT type/code (cast iron)
- 0063AS4831
- Factory code (SIT)
- 0845061
- Inlet pressure (Pi max)
- 60 mbar
- Outlet pressure (Po)
- 1-37 mbar
- EV1 (1st solenoid valve)
- 230V~50Hz, 9.2 VA class B
- EV2 (2nd solenoid valve/modulating)
- 230V~50Hz, 2.8 VA class J
- Modulator MD
- MAX 17V DC, MAX 165 mA
- Ambient temperature
- 0/60°C
- Manufacturing (week/year)
- 0110
- Batch
- 2031508
- This unit is currently cataloged as 'Fagor Contract CA 20EN'; the confirmed boiler models for this part are FE20E, FE20E1N, and FEE20.
Frequently asked questions about the gas valve MU0809100
Does this SIT 845 SIGMA gas valve fit the Fagor FE20E1N?
Who manufactures this valve for the Fagor FEE20?
What working pressures does this valve have in the Fagor FE20E?
When should this gas valve be replaced in a Fagor FEE20?
How many models are compatible with the SIT 845 SIGMA gas valve?
What is the reference for this gas valve?
Spare parts related to Fagor Eco Compact FE-20E
