Biasi Boiler Advance 25C Expansion Vessel 7L BI1462100

This biasi advance 25c expansion vessel 7l supports safe pressure control by absorbing water expansion as the system heats up. However, when the internal diaphragm weakens or loses charge, pressure can rise quickly, the PRV may discharge, and you may notice repeated filling-loop top-ups or boiler lockouts. Therefore, replacing the correct BI1462100 vessel helps stabilise pressure, improves system operation, and reduces nuisance shutdowns.

Compatibility :

• Advance: 25C, 25S, 30C, 30S, 35C
• Advance Plus ErP: 16S, 25C, 25S, 30C, 30S, 35C
• Inovia: 16S, 25C, 25C ErP, 25S, 25S ErP, 30C, 30C ErP, 35C, 35C ErP

Important fitting advice

We recommend that all parts are fitted by a fully qualified Gas Safe registered engineer. If you need help confirming the right part, contact us our team has 10+ years of boiler spares knowledge and friendly chat support to help you quickly.

Delivery

At Boiler Spares Hub, we dispatch orders within 1 working day (Monday-Friday). Orders placed outside working days will be dispatched on the next working day. For delivery options available for this product, please add it to your basket or check our delivery options page.

Returns

We accept 30-day returns. Returns must be in an unopened, sealed box. If we find the item has been used or installation was attempted, we may refuse the return.

Frequently Asked Questions (FAQs)

1. What does an biasi advance 25c expansion vessel do?
It absorbs water expansion as the heating warms up, helping keep system pressure stable.

2. Signs the vessel may have failed?
Frequent pressure drops, repeated topping up, pressure rising quickly when heating runs, or PRV discharge outside.

3. Will this fit my boiler?
Check your boiler model is listed in the compatibility section and match part number BI1462100.

4. Is this a DIY fitting part?
It’s recommended to use a Gas Safe registered engineer for safe installation and correct pressure charging.

5. Any setup tips after replacement?
System pressure usually needs restoring and the system may require bleeding—follow the boiler manual/engineer guidance.