Sime "friendly" boiler no heating or hot water hel

[ladydisco]

Please can anyone advise me ?

I have a Sime "friendly" combi boiler that yesterday, emitted a horrific sound (similar to a car scraping an exhaust along the road). This morning, I awoke to silence, cold radiators and no hot water. The pilot light is still on, but the boiler will not fire up. As having no idea about boilers, I was wondering if it is the pump? I would appreciate any initial help, as I am concerned about calling someone out and them scaring me with a bill for hundreds of pounds.
Thankyou

 

[kevplumb]

sounds as if the high limit stat has tripped

 

[ladydisco]

Thanks for your help Kev

I can suggest that to the guy and he may think I know more than I do, less chance of being ripped off. Cheers!!!