I've got an old Potterton glow worm 92/100 boiler that is making kettling noises and presumably needs cleaning out. Is this easy to do and do you need any special tools/seals etc?
I should be very careful as I have just read that some of these older boilers can contain ACM's ie asbestos containing materials and your boiler is one that is listed.Get a professional in to clean it and service and dont use a conventional vacuum cleaner.