hi i am am a gas fitter with 20 years experiance working on installations boiler repairs and servicing with experiance in all boiler aspects from 20 years ago till the present day i am currently still working in the gas servicing/boiler breakdown industry and wish to pass on my profesional advice to consumers who are sick of being ripped off!!!! I have seen countless so called professionals starting off in this industry looking for ££££££s having done a two week course and then calling themselves professional CORGI REGISTERED boiler experts hoping to make a fast buck
every gas fitter worth his salt will look for faults with a multimeter or based on past experiance have a basic knowledege of the boiler in question and having worked on said boilers before have a grasp on what the common problems are asociated with the appliance. All combi boilers have a sequence of operation before you get heat to your radiators or hot tap all combi boilers follow this sequence it is just a case of finding out where the sequence has stopped
p.s sometimes the problem is mechanical) i.e hydraulics mechanical function