Boiler Expansion Vessel Ref. 122155370 - Laura 20 and Victoria 20/20
The expansion vessel of the boiler - Laura 20 and Victoria 20/20 is a component that absorbs the increase in water volume when heated. When it fails, you may notice a loss of pressure, as well as the boiler pressure fluctuating sharply, which can cause the safety valve to leak. This vessel is compatible with models such as Laura 20, Victoria 20, and Victoria 20/20, among others. It is recommended to replace it when you observe these symptoms of improper operation.
Baxi Roca boilers compatible with reference 122155370
Expansion vessel with reference 122155370. 14 verified compatibilities: Victoria 20 and Victoria 20/20.
Proven compatibility
| Boiler model | Family | Verification |
|---|---|---|
| Baxi Roca Victoria 20 | Victoria | Contrasted |
| Baxi Roca Victoria 20/20 | Victoria | Contrasted |
| Baxi Roca Victoria 20/20 F | Victoria | Contrasted |
| Baxi Roca Victoria 20/20 T | Victoria | Contrasted |
| Baxi Roca Laura 20 | Laura | Contrasted |
| Baxi Roca Laura 20 F | Laura | Contrasted |
| Baxi Roca Laura 20/20 | Laura | Contrasted |
| Baxi Roca Laura 20/20 F | Laura | Contrasted |
| Baxi Roca Laura 20 AF | Laura | Contrasted |
| Baxi Roca RS 20 | RS | Contrasted |
| Baxi Roca RS 20/20 | RS | Contrasted |
| Baxi Roca RS 20/20 F | RS | Contrasted |
| Baxi Roca R 20/20 | R / NR | Contrasted |
| Baxi Roca NR 15/20 | R / NR | 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. 122155370 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 122155370. 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 122155370 solves
The expansion vessel absorbs the expansion of water when heated. These are the typical symptoms and what to do:
Common symptoms and faults
- 01
When the boiler starts heating, the pressure gauge rises quickly and sometimes the safety valve is activated.
Cause: The vessel has lost pressure in the air chamber or has a damaged diaphragm, allowing all the water expansion to pass into the circuit.
With the circuit without water pressure, press the valve of the expansion vessel: if it does not release air forcefully or releases water, the membrane is broken.
- 02
There are banging noises in the pipes when turning the heating on or off.
Cause: Without the air chamber of the vessel that dampens sudden pressure changes, the water hammer reaches the installation directly.
Check if the glass feels heavy to the touch or sounds solid when tapped; a glass full of water no longer dampens anything.
- 03
The glass weighs much more than it seems given its size.
Cause: This usually happens because the inner diaphragm is broken and the expansion vessel has filled with water instead of maintaining air.
Knock on the glass with your knuckles at various points: if it sounds full all over the surface, it is flooded and needs to be checked.
- 04
Water is leaking from the discharge pipe of the safety valve almost constantly.
Cause: When the expansion vessel does not absorb the water expansion properly, the pressure rises above the set limit and the valve drains to protect the circuit.
First, check the condition of the safety valve and its gasket, because a worn valve can also leak without the vessel being involved.
Fault codes for Baxi Roca that this part resolves.
| Code | Fault | Diagnosis and solution |
|---|---|---|
| 06 | Air bags | There may be air pockets in the heating circuit, which prevents the proper circulation of water. This could be caused by a faulty expansion vessel. Check the radiators and bleed the air if necessary. If the problem persists, consider checking the expansion vessel. |
| 14 | Air bags | There may be air pockets in the heating circuit, which prevents the proper circulation of water. This could be caused by a faulty expansion vessel. Check the radiators and bleed the air if necessary. If the problem persists, consider checking the expansion vessel. |
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 Baxi Roca expansion vessel 122155370
- Catalogue reference
- 122155370
- Brand
- Baxi Roca
- Type of part
- Expansion vessels
- Units in stock
- 0 units
- Status
- Refurbished
- Warranty
- 1 year
- Shipping
- 1-2 business days
- Return
- 14 days
Manuals and technical documentation
Official documentation of the boiler, useful for locating the part and cross-referencing the fault codes.
- Baxi Roca Laura 20/20 F Manual (PDF)Document © Baxi Roca, provided as a technical reference.
Frequently asked questions about the expansion vessel 122155370
Does this vessel also work for a Victoria 20/20F boiler?
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