
Pressure switch Sime 6225724 for Sime Metropolis 25 BF boiler
When you decide to turn on the heating in your home, the pressure switch Sime 6225724 is responsible for checking the air pressure and authorizing the operation of the boiler. If this part fails, it is possible that the boiler will not start or will lock out, even if the actual pressure is adequate. This model is compatible with the boiler Metropolis 25 BF, among others in the range. If you experience the fault code AL 01 or a flashing green LED, it could indicate a problem with the flue gas outlet, related to the pressure switch. It is recommended to replace this part when you notice these symptoms.
VAT included
Consult via WhatsAppSime boilers compatible with reference 6225724
Pressure switch with reference 6225724. Three confirmed compatibilities: Format Zip 5-25 BF and Format Zip 5-25 BF TS.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Sime Format Zip 5-25 BF | Format / Format Zip | Contrasted |
| Sime Format Zip 5-25 BF TS | Format / Format Zip | Contrasted |
| Sime Metropolis 25 BF | Metropolis | 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. 6225724 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 6225724. 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 6225724 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 boiler tries to ignite, the fan spins, but it stops and gives a fault before the flame comes out.
Cause: The pressure switch does not close the contact because it does not detect the air pressure difference that the fan should generate, and for safety reasons, the boiler blocks the ignition.
Check that the silicone tubes going from the pressure switch to the fan and the flue are not bent, disconnected, or have condensed water inside.
- 02
The fault appears depending on how the boiler is installed, more in some systems than in others.
Cause: This pressure switch has a different adjustment depending on whether it is installed horizontally or vertically, and a change in the air intake can alter the reading.
Check the installation orientation of the boiler and ensure that the connection fitting has not been replaced with one of a different size.
- 03
The boiler locks out as soon as the fan starts, without attempting to ignite the flame.
Cause: The internal microswitch does not change state if the diaphragm is dirty, wet, or stuck, even if the extractor is working properly.
With the boiler off, gently blow through the pressure intake pipe and listen for the pressure switch to click; if it doesn't, the fault is in the part.
- 04
The fault comes and goes, some days it starts up fine and other days it gets blocked.
Cause: A contact that starts to fail due to wear may close sometimes and sometimes not, before completely stopping functioning.
Check the condition of the fan: if it spins with noise, slower than usual, or has difficulty starting, rule out the fan first before considering the part to be good.
Fault codes for Sime that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| AL 01 | Problem with the flue gas outlet | The air pressure switch does not activate when the fan starts because there is not enough depression or it is faulty. To check it, use a differential manometer and verify the continuity of the microswitch. Also, check the silicone tubes, the fan, and the ducts. |
| Flashing green LED | Fault in the fan or flue pressure switch | The pressure switch does not close because there is insufficient draft or it has an internal fault. Check the continuity of the contact when the fan is running and measure the depression with a manometer. Additionally, clean or unclog the pipes and the chimney. |
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 Sime 6225724 pressure switch
- Catalogue reference
- 6225724
- Brand
- Sime
- Type of part
- Pressure switches
- 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.
- Internal code
- 605.99748
- Commercial reference (Sime)
- 6225724
- Contact
- 1(0.5)/250~
- Batch code
- KMIEGI
- Horizontal setting
- 52/42 Pa
- Vertical setting
- 62/52 Pa












