Air Pressure Switch VCM 242/1 E - Cod. 605.99390
Air pressure switch (also known as differential or flue pressure switch), a component that compares the pressure generated by the extractor with a set value and allows or blocks the ignition of the burner based on the result. Replacement requires first confirming the fault of the part through technical diagnosis, even when the boiler does not ignite, is blocked with the extractor running, or shows a fault code for lack of draft. Factory setting: 135/120 Pa.
Vaillant boilers compatible with reference 050557
Pressure switch with reference 050557. Six confirmed compatibilities: VCM 182 E and VCM 182/1 E.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Vaillant VCM 182 E | VCM Turboblock | Contrasted |
| Vaillant VCM 182/1 E | VCM Turboblock | Contrasted |
| Vaillant VCM 242 E | VCM Turboblock | Contrasted |
| Vaillant VCM 242/1 E | VCM Turboblock | Contrasted |
| Vaillant VCM 282 E | VCM Turboblock | Contrasted |
| Vaillant VCM 282/1 E | VCM Turboblock | 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. 050557 is the part for your boiler
The part reference, model, and equipment revision must be verified against the manufacturer's documentation.
- Find the reference printed on the installed part and check whether it matches the catalogue reference 050557. 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 that require diagnosis in the pressure switch 050557
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 boiler locks up with the fan running at full speed and without igniting the flame.
Cause: The differential pressure switch does not receive sufficient depression even though the extractor is operating at its maximum capacity.
Check that the air intake grille and the flue outlet are not obstructed by dirt or, in winter, by ice.
- 02
The flue fault appears right after cleaning or inspecting the boiler.
Cause: When handling the flue pipe, it is easy for the silicone tube of the pressure switch to become dislodged or pinched.
Visually check the path of the silicone tube of the pressure switch after any intervention in the duct.
- 03
The boiler works well almost always, but it fails just after a power cut or when turning it back on.
Cause: A pressure switch at the limit of its travel may not stabilize in time on the first attempt after reconnecting the power.
Note whether the fault occurs always on the first ignition of the day or after power supply interruptions.
- 04
The extractor sounds different than usual just before the boiler locks out.
Cause: A fan that loses revolutions does not generate the pressure differential that the pressure switch needs to operate correctly.
Listen to see if the extractor sounds more strained or weaker than usual before ruling out the pressure switch.
Vaillant fault codes that require diagnosis
| Code | Fault | Technical checks |
|---|---|---|
| F.33 | Pressure switch fault | The air pressure switch does not switch (does not close/open when the fan starts/stops) due to obstruction in the pressure intake/hose or a defective pressure switch; check continuity by applying pressure and inspect hoses, pitot intake, and air-smoke draft. |
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.
Vaillant 050557 pressure switch datasheet
- Catalogue reference
- 050557
- Uniclima internal SKU
- PTVCM242
- Brand
- Vaillant
- Type of part
- Pressure switches
- Units in stock
- 34 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- Delivery time shown at checkout
- Return
- 14 days
Part data and available documentation
Contrast the label codes, PCB, and revision with the installed part; they are not necessarily equivalent references.
- Component code
- 605.99390
- Switching pressure (open/close)
- 135/120 Pa
- Contact current/voltage
- 0.2(0.1)/30~
- Additional code
- 00FDHJ
- Batch code / short reference
- JV 050546 / J16
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Vaillant VCM 182/1 E Manual (PDF)Document © Vaillant, provided as a technical reference.
Frequently asked questions about the pressure switch 050557
Is this air pressure switch suitable for the VCM 242/1 E boiler?
What fault indicates that the air pressure switch of the VCM 242/1 E needs to be replaced?
What pressure does the air pressure switch of the VCM 242/1 E switch?
How many models are compatible with the VCM 242/1 E air pressure switch?
What other models are compatible with the VCM 242/1 E air pressure switch?
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