How to work this mechanical timer dial

[pilotman14]

Hi all,

I have just moved into a rented property and it have a unvented heater tank for the hot water. I am getting no hot water at all and just wondering if the knotches on this timer dial need to be in or out for it to be on?
I suspect the timer is broken as when I set the current time it doesn't move and after a few hours it stays at the same time.
"Axiom 24 Hour Mechanical Timer 16A"

Cheers

 

[polesapart]

I suspect the timer is broken

or switched off. Any adjacent wall switches?

 

[pilotman14]

or switched off. Any adjacent wall switches?

Everything is switched on, including the circuit breaker

 

[pilotman14]

or switched off. Any adjacent wall switches?

It has 2 switches, one says water heater and the other says boost. Both are on

 

[oilhead]

The pins should be out for the timer to be on, but if the clock does not move then nothing will happen,