Boilermate 2000

I recently moved in to this property and have this boiler. There is also another small gas boiler in the garage (not sure what it is for)

I have no major instruction manual, and today I put the heating on override as I have managed how to do the timer. I accidently turned off the heating but turned it straight back to timer. Today when I came home the heating was on but it has slowly gone off completely. I have checked the thermostat, the timer clock (which is working). The power light is on but that is the only light I can see.

I have a contract with Homeserve, but have no idea what is wrong with a boiler I am totally unfamiliar with. I seem to have hot water.
Not sure what I should do next it is freezing outside.

Hi
You can download the User book And Installation manual.
Free from Gledhill website.
Mike