
Zilmet Expansion Vessel for Ariston Basic 23 MFFI Boiler, Ref. 564492
The Zilmet expansion vessel absorbs the increase in water volume when heated in the Ariston Basic 23 MFFI boiler, Ref. 564492. When it fails, you may notice that the pressure fluctuates sharply, and the safety valve starts to leak. This component is compatible with several Ariston models, such as Basic 23 M, Dia 20 M, and Meta 24 MFFI, among others. It is recommended to replace it when these symptoms are detected to avoid more significant issues in the heating system.
VAT included
Consult via WhatsAppAriston boilers compatible with reference 564492
Expansion vessel with reference 564492. 11 verified compatibilities: Basic 23 M FFI and Basic 23 M.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Ariston Basic 23 M FFI | Ariston | Contrasted |
| Ariston Basic 23 M | Ariston | Contrasted |
| Ariston Dia 20 M | Ariston | Contrasted |
| Ariston Dia 20 MFFI | Ariston | Contrasted |
| Ariston Dia 24 M | Ariston | Contrasted |
| Ariston Dia 24 MFFI | Ariston | Contrasted |
| Ariston Meta 20 MFFI | Ariston | Contrasted |
| Ariston Meta 24 MFFI | Ariston | Contrasted |
| Ariston ARX 24 BFFI | Ariston | Contrasted |
| Ariston SP 20 | Simat | Contrasted |
| Ariston SP 24 | Simat | 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. 564492 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 564492. 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 expansion vessel 564492 resolves.
The expansion vessel absorbs the expansion of water when heated. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
The pressure gauge of the boiler gradually loses pressure and water needs to be replenished every so often.
Cause: The expansion vessel no longer retains the pre-charge air or the membrane has been perforated, which prevents compensating for the increase in water volume.
With the boiler cold and the circuit without pressure, check the expansion vessel valve with an air pressure gauge: if it does not show pressure, confirm the fault before replacing it.
- 02
Water is coming out of the safety valve, even with the heating turned off.
Cause: When the air cushion in the tank is missing, any small expansion of the water causes an increase in pressure that activates the gas valve.
Try manually bleeding the safety valve once: if it closes properly again and stops leaking, the problem may be with the expansion vessel and not with the valve itself.
- 03
There are noticeable knocks or water hammer noises in the heating pipes when the boiler starts up.
Cause: A vessel without cushioning capacity allows the pressure surge when starting the pump to be transmitted directly through the circuit.
Press the body of the glass with your hand: if it offers no elastic resistance, it has no air and is a clear indication before replacing it.
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 Ariston expansion vessel 564492
- Catalogue reference
- 564492
- Brand
- Ariston
- Type of part
- Expansion vessels
- 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.
- Manufacturer
- ZILMET
- Code on label (moderate confidence reading)
- 531/A
- Batch or serial code (moderate confidence reading)
- 5C009/95







