Best CH expansion vessel

[fiddler3]

Hello again from enthusiastic amateur. Previous request for help re daughter's pressure reducing Ideal boiler helped me to get it sorted economically.
Today my query is re my own system with Worcester Bosch system boiler where I think the built in expansion vessel is inadequate or faulty. I would like to add a separate vessel at about 12 litres capacity and would be grateful for recommendations on which manufacturer is likely to supply me with one that wont expire in a couple of years (reviews on Toolstation / screwfix)

 

[ShaunCorbs]

Around 1l per rad needed for expansion

Reflex expansion vessel are the best tbh

 

[king of pipes]

Flexcon made by Flamco are a reliable vessels . Kop

 

[Stigster]

I've always had reliable performance from Zilmet vessels.

 

[SimonG]

Usually zilmet, but to be honest I just grab what they have.

 

[Best]

Usually I have decent lifespan with expansion vessels of any brand.
Merchants sell different varying brands.
If the vessel is plenty large enough for system and serviced regularly it hopefully will last more than 10 years