Ravenheat RSF 100ET have no hot water or heating?

When trying to get a shower this morning discovered i have no hot water (it was working ok last night), checked the boiler and the light is on as normal so put the heating on to try that and the radiators are not getting warm either. The pressure was low on boiler but sorted that out and got that back up, still no hot water or heating. I can hear a noise coming from boiler but doesn't seem as loud as usual (could just be me though) and there is no smoke coming out of outside vent (prob as nothing being heated). I am going to call someone out but don't want to be ripped off, any ideas on what it could be? Thanks for any help.