life span of lynx electronic combi boiler?

Your boiler was last made in 1972
It has a power rating of 23.45kW
It is very inefficient at 65% compared to a modern boiler's 90%
It is eligible for the £400 scrappage scheme but not in Wales
You may continue to use it legally until it becomes (is declared) unsafe
There is no obligation on you otherwise to replace it - but I think I would if it were mine

Source...

http://www.homeheatingguide.co.uk/efficiency-tables.php?model=000653#efficiency

Good luck...

Peccavi
January 2010