Go for a Worcester easy control instead of the nest then, it's more expensive but it'll be covered under the he guarantee, the nest won't beI have a good installer who has come reccomended - This is why I want to change the boiler - Its actually still working but it looks like its on its last legs and previously had sludge .....
So now i have an installer I just need to find a good boiler - Its a small two bed flat with combi boiler already there and easy access as on ground floor.
I know I need a flue / magnatec filter new nest controls (we have an old honeywell wired thermostat) and a boiler!!! The worcester 2000 fits the bill as it is 25KW and the rightish size but without nest compatability it sucks!~