Modulating Gas Valve Actuator for Isofast F 30 E H-MOD - Ref. S1071400
The modulating gas valve actuator for Isofast F 30 E H-MOD is a component that regulates the flow of gas to the burner, following the instructions of the control board. When it fails, the boiler may not ignite, experience flame lockouts, or have modulation issues. Symptoms may include faults such as F.26, F.27, or F.28, among others. This actuator is compatible with other models in the Isofast range, as well as with various boilers from the Themafast, Themaclassic, Themaplus, Thema, Thematek, and Isosplit ranges. It should be replaced when these faults in the boiler's operation are detected.
VAT included
Consult via WhatsAppSaunier Duval boilers compatible with reference S1071400
Gas valve with reference S1071400. 24 verified compatibilities: Themafast C 24 E and Themafast C 25 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval Themafast C 24 E | Themafast | Contrasted |
| Saunier Duval Themafast C 25 E | Themafast | Contrasted |
| Saunier Duval Themafast F 24 E | Themafast | Contrasted |
| Saunier Duval Themafast F 25 E | Themafast | Contrasted |
| Saunier Duval Themaclassic C 24 E | Themaclassic | Contrasted |
| Saunier Duval Themaclassic C 25 E | Themaclassic | Contrasted |
| Saunier Duval Themaclassic F 24 E | Themaclassic | Contrasted |
| Saunier Duval Themaclassic F 25 E | Themaclassic | Contrasted |
| Saunier Duval Themaplus C 24 E | Themaplus | Contrasted |
| Saunier Duval Themaplus F 24 E | Themaplus | Contrasted |
| Saunier Duval Themaplus F 25 E | Themaplus | Contrasted |
| Saunier Duval Thema C 24 E | Thema | Contrasted |
| Saunier Duval Thema F 24 E | Thema | Contrasted |
| Saunier Duval Thema F 25 E | Thema | Contrasted |
| Saunier Duval Thematek C 24 E | Thematek | Contrasted |
| Saunier Duval Thematek F 24 E | Thematek | Contrasted |
| Saunier Duval Isofast F 30 E H-MOD | Isofast | Contrasted |
| Saunier Duval Isofast F 35 E H-MOD | Isofast | Contrasted |
| Saunier Duval Isosplit C 28 E | Isosplit | Contrasted |
| Saunier Duval Isosplit F 30 E | Isosplit | Contrasted |
| Saunier Duval Isosplit F 35 E | Isosplit | Contrasted |
| Saunier Duval Opalia C 16 E | Opalia | Contrasted |
| Saunier Duval Opalia F 14 E | Opalia | Contrasted |
| Saunier Duval Opaliaplus F 17 E | Opalia | 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. S1071400 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 S1071400. 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 S1071400 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 does not ignite the burner even though it requests heat.
Cause: The modulating actuator does not open the minimum gas flow required for the flame to ignite.
Check for air in the gas circuit after a recent supply cut; bleed before suspecting the actuator.
- 02
The flame rises and falls abruptly, instead of modulating smoothly according to demand.
Cause: The modulating actuator does not properly control the opening and operates in an all-or-nothing manner instead of gradually.
Observe the flame through the sight glass for a few minutes; if it jumps between very high and almost extinguished without intermediate steps, it is typical of the actuator.
- 03
The boiler locks out with a flame or ignition fault code shortly after starting.
Cause: If the actuator does not stabilize the gas opening, the flame is detected as insufficient or unstable, and the control unit shuts off for safety.
Check if the blockage occurs at the same point in the ignition cycle; this helps to distinguish between the electrode and the actuator.
- 04
The gas consumption seems irregular, with the boiler providing more or less flame than it should.
Cause: An actuator that does not respond linearly to the modulation signal leaves the flame uncontrolled even if the rest of the system requests a constant level.
Note if the problem coincides with changes in ambient temperature or is constant; if it is constant, it points more towards the actuator than the sensor.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| F.26 | Fault: gas valve not functioning. | The Honeywell gas valve S1071400 does not open because the stepper motor/solenoids do not receive or do not respond to the command. Check the connector/harness, coil continuity, and ensure that the valve is powered during the ignition attempt; also check that there is no pressure at the outlet during the attempt. |
| F.27 | Safety shutdown: flame simulation. | Defective/leaky gas valve S1071400 allows gas to pass when it should be closed, simulating a flame. Check tightness and closure: perform a pressure drop test at the burner inlet and confirm that ionisation ceases when the gas is cut off. |
| F.28 | Start-up fault: ignition failed. | The gas valve S1071400 does not open or is poorly calibrated, preventing the gas supply during ignition. Check that the electronics command opening (voltage to coils) and that pressure appears at the outlet during the attempt; if it does not open or is erratic, replace/adjust. |
| F.61 | Fault: gas valve control. | Electrical defect in valve S1071400 (coil short-circuited/grounded) or in its wiring causes activation fault. Check coil resistance/insulation and continuity of the harness to the PCB; if there is a ground leak or values are out of range, replace the valve. |
| F.62 | Gas valve fault. Disconnection delay. | The S1071400 valve takes time to close or remains unsealed, maintaining gas after the stop command. Check closing time and tightness (pressure/ionisation test after cut-off); if gas or residual flame persists, replace the valve. |
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 gas valve S1071400.
- Catalogue reference
- S1071400
- Brand
- Saunier Duval
- Type of part
- Gas valves
- Units in stock
- 1 unit
- 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.
- voltage
- 24 VDC
- power
- 6 VA
- gas
- NATURAL GAS
- protection
- IP 20
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval Isofast F 35 E H-MOD Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the gas valve S1071400
Is this modulating gas valve actuator compatible with the Isofast F 30 E H-MOD?
How many models are compatible with the MVGTF25MOD modulating gas valve actuator?
What symptoms indicate that I should replace the modulating gas valve actuator?
What fault codes are documented for this actuator?
Is this actuator suitable for the Themafast range?
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