sounded like my boiler was going to blow up,its a boilermate2, i switched it on for the first time since the summer, thermostat working, radiators were turned on, green light came the bottom of boiler in airing cupboard water still hot but radiators stone cold. then really loud noises, i rushed up and switched the whole lot off, then tried it again 20 minutes later and same thing, sounds llike someones dropping bombs!. the pump was apparantly changed in the summer as had the same problem then but without the loud noises, the radiators seemed fine got hot so it was switched off for a few months, and now this! any suggestions? i know the pump that was supposodly replaced wasnt new, if indeed it was replaced at all? im beginning to doubt it was, because it was the guy i bought the house from!! do you think i should bleed the radiators, although all of these were stone cold when heating was switched on or do you think i should replace the pump myself? there are two pumps with this boiler, also it could be the small boiler in kitchen thats faulty ?which has to be switched on to allow heating to come on...i had trouble determining which boiler the noise came from as loud as it was!! arrrghh!! can anyone help? thankyou. anything might help and would be appreciated.