Just had my boiler done at a meagre 12 years old, but replaced with a brand I'd at least heard of. I think if the boiler was built in the last 20 years it won't last very long, but much older boilers can last a lifetime.
You'll never got more than that out a new boiler, 12-15 you'll be doing well and even now the long warrantys are gonna be fun when they get to the later end of the 10 years.
Just had my boiler done at a meagre 12 years old, but replaced with a brand I'd at least heard of. I think if the boiler was built in the last 20 years it won't last very long, but much older boilers can last a lifetime.