Saunier Duval Themafast F 25 E H Air Pressure Switch MOD Ref. S5744100
In the Saunier Duval Themafast boilers, the air pressure switch Themafast F 25 E H MOD controls the air pressure and allows the boiler to operate correctly. If this part fails, the boiler may not start or may lock out, even if the actual pressure is adequate, displaying fault code 02: Air flow safety. This pressure switch is compatible with several models such as the F 25 E H-MOD, F 30 E, and others from the Themafast range, among others. Replacement is carried out when starting failures or operational lockouts occur.
Saunier Duval boilers compatible with reference S5744100
Pressure switch with reference S5744100. 21 verified compatibilities: F 30 E H-MOD and F 35 E1.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Saunier Duval F 30 E H-MOD | Isofast | Contrasted |
| Saunier Duval F 35 E1 | Isofast | Contrasted |
| Saunier Duval F 35 E H-MOD | Isofast | Contrasted |
| Saunier Duval F 28 E2 | Isomax | Contrasted |
| Saunier Duval F 28 EA | Isotwin | Contrasted |
| Saunier Duval F 30 E H-MOD | Isotwin | Contrasted |
| Saunier Duval F 30 E | Isosplit | Contrasted |
| Saunier Duval F 35 E | Isosplit | Contrasted |
| Saunier Duval F 35 E H-MOD | Isosplit | Contrasted |
| Saunier Duval F 25 E | Themafast | Contrasted |
| Saunier Duval F 25 E H-MOD | Themafast | Contrasted |
| Saunier Duval F 30 E | Themafast | Contrasted |
| Saunier Duval F 30 E H-MOD | Themafast | Contrasted |
| Saunier Duval F 25 E | Thema | Contrasted |
| Saunier Duval F 25 E STL | Thema | Contrasted |
| Saunier Duval F AS 25 E | Thema | Contrasted |
| Saunier Duval F 25 E | Themaplus | Contrasted |
| Saunier Duval F 30 E | Themaplus | Contrasted |
| Saunier Duval F AS 30 E | Themaclassic | Contrasted |
| Saunier Duval F 17 E | Opalia | Contrasted |
| Saunier Duval F 17 E | Opaliafast | 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. S5744100 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 S5744100. 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 pressure switch S5744100 resolves.
The pressure switch controls the air or water pressure to authorize operation. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The extractor works, but the boiler does not start and gets locked.
Cause: The pressure switch does not detect the extractor's depression, which prevents the boiler from igniting.
Check that the silicone tubes between the pressure switch and the fan are not pinched, bent, or disconnected.
- 02
The boiler does not ignite and the fan does not spin as it should.
Cause: If the extractor does not reach the necessary speed, it does not create the depression that the pressure switch needs to operate, even if it is functioning properly.
Check that the fan rotates freely by hand with the boiler unplugged, without any friction or resistance.
- 03
The problem occurs after cleaning or inspecting the boiler.
Cause: When disassembling the flue or the extractor, it is possible that some pipe is not properly positioned, causing the same fault as a broken pressure switch.
Check that all pipes and fittings are properly connected after any handling before considering the spare part.
Fault codes from Saunier Duval that this spare part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 02 | Air flow safety. | The air pressure switch S5744100 does not switch when the fan starts or does not detect the depression due to obstruction in tubes/venturi; check with a multimeter or manometer that the pressure switch changes state with the fan running and inspect tubes and connections. |
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.
Datasheet for Saunier Duval pressure switch S5744100
- Catalogue reference
- S5744100
- Brand
- Saunier Duval
- Type of part
- Pressure switches
- Units in stock
- 0 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.
- Set (opening/closing)
- 59/51 Pa
- Contact electric charge
- 1(0.5) A / 250 V~
- Component code
- 605.99534
- Internal code
- 116189
- Batch code
- EJMADF
- Manufacturing date
- week 03 of 2005
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Saunier Duval F 25 E H-MOD Manual (PDF)Document © Saunier Duval, provided as a technical reference.
Frequently asked questions about the pressure switch S5744100
Does this pressure switch Ref. S5744100 work for my Saunier Duval Isofast F 35 E1?
What are the opening and closing pressure settings for the pressure switch S5744100?
What code is engraved on the pressure switch of the Themafast F25E?
What fault indicates that this pressure switch needs to be replaced in the Opalia F 17 E?
Spare parts related to Saunier Duval Themafast
