Leaking boiler help, don't think its serviced, lazy landlord. (Pics included)?

Sorry I know nothing about boilers and even if I did it is illegal in England for anyone other than a qualified engineer to touch it. Your landlord is breaking the law I reckon. Boilers should have a safety certificate to show it has been serviced regularly and is safe to use. Many people have died from carbon monoxide (you can't smell it) poisoning from boilers, which was why the law was introduced. I think once you mention this to him he will immediately arrange for it to be fully serviced and supply you with a safety certificate. This should be renewed every year by him.