Ariston Microgenus 23 MFFI / 27 MFFI pressure switch
In the Ariston Microgenus 23 MFFI and 27 MFFI boilers, the pressure switch is a component that controls the air or water pressure and allows the boiler to operate. If this part fails, the boiler may not start or may lock out, even if the pressure is correct, which can generate fault codes E33 or E34. This pressure switch is compatible with models such as CODEX27, GENUS30MFFI, and LINDA23, among others. It is recommended to replace it when these symptoms or fault codes occur.
VAT included
Consult via WhatsAppAriston boilers compatible with reference 571651-01
Pressure switch with reference 571651-01. Four confirmed compatibilities: CODEX27 and GENUS30MFFI.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Ariston CODEX27 | Codex | Contrasted |
| Ariston GENUS30MFFI | Genus | Contrasted |
| Ariston F23MFFI | F (MFFI) | Contrasted |
| Ariston LINDA23 | Beautiful | 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. 571651-01 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 571651-01. 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 571651-01 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 can be heard, but it stops immediately and does not produce a flame.
Cause: The pressure switch does not close the contact because it does not detect the depression generated by the extractor, and the control board cuts the cycle before opening the gas.
Check that the fan spins freely and at a good speed before checking the pressure switch: if the extractor is slow, the pressure switch will never close even if it is functioning properly.
- 02
The boiler is locking out with a fault code related to the flue or smoke evacuation.
Cause: This pressure switch exists precisely for that: to monitor that the air-flue gas circuit has the minimum depression before allowing ignition.
Check the flue duct for any blocked, crushed, or excessively long sections before replacing the part.
- 03
The fault is intermittent: sometimes it starts up properly and other times it gets blocked, especially with strong wind outside the house.
Cause: Small pressure variations in the outlet duct cause a worn pressure switch to switch unstably.
Note if the fault coincides with windy days; if so, check the flue gas outlet terminal first before confirming the replacement.
- 04
Upon opening the boiler, the silicone tubes of the pressure switch are seen to be loose, hanging, or cracked.
Cause: Without a sealed pressure take-off, the pressure switch cannot read the fan signal correctly, even if the component itself is functioning properly.
Make sure that the two silicone tubes are properly fitted into their connections and without cracks before purchasing the pressure switch.
Fault codes for Ariston that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| E33 | The air pressure switch (flue pressure switch) is closed before the ignition sequence. | The Honeywell pressure switch 571651-01 can become 'stuck' (contacts closed without depression) or receive false pressure due to obstruction/tubes; the PCB detects premature closure. Check the micro continuity and that it opens/closes by applying depression and inspecting tubes/venturi. |
| E34 | The air pressure switch (flue pressure switch) does not close when the fan runs. | If the 571651-01 does not switch (rigid diaphragm, faulty micro) or no pressure reaches the pressure switch, the boiler does not receive flue authorization. Check with a differential manometer and micro continuity with the fan running; inspect tubes/venturi/fan. |
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 Ariston Pressure Switch 571651-01
- Catalogue reference
- 571651-01
- Brand
- Ariston
- Type of part
- Pressure switches
- 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.
- Setting / pressure
- P=1.08 mbar, max. 6 mbar
- Condenser
- 0.1µF / 125V~
- CE code
- CE-0063AP3085/1
- Manufacturing code
- 0502F
- Place of manufacture
- Made in China
Frequently asked questions about the pressure switch 571651-01
Is this pressure switch compatible with the Ariston Microgenus 23 MFFI?
What is the set pressure of the pressure switch in the photographed Microgenus?
What information can I read on the label to verify that it is my pressure switch for the Microgenus 23/27 MFFI?
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