What could be wrong with my boiler?

I think the pilot light keeps going out… basically the boiler is working…heating water…and central heating is working but after a while it seems to stop… but the boiler is still making a whirring noise…If I run the kitchen hot water tap it just comes through cold… I then have to press the reset button and it comes back on again.

Any ideas what’s wrong with it and if it’s something I can fix or if I really need to contact my landlord.. (he can be a bit slow at getting things done…so if I can sort it myself without cost or blowing the house up that would be cool!).