Floor heating timer on boiler

[Mark a]

I'm trying to use an underfloor heating programmer/timer on my Worcester Boiler to control the central heating ?
The switched output from the programmer is 240v at 16amps yet it will not fire up the boiler ?
I cant understand why.

Thanks

 

[Murdoch]

Has it ever worked?

has anything been changed recently ?

 

[ShaunCorbs]

You haven’t just wired into the feed of the boiler eg when the timer comes on the boiler lights up ?