How many people who design new boilers are GasSafe registered ?
Do you know any designers who are not registered for gas work?
Boiler in the picture, IIRC, was never made as rear glued appliance
DanR I was mulling over what you said above. How difficult is it to cut the mastic and do a proper check.
This lack of imagination is similar to my neighbour, whom I gave ample advice and 'education' in what I know of boilers and suggested a Gash. Blinkers on by both her and fitter ( I did not want the job), a Failant has been installed on a system that is plus 35 years young. She is oressurising the system every few days. Installer does not want to come back- how much effort is needed to replace a known leaking rad valve when system is drained down.
SWAMBO is in my case and wants me to replace the valve as she is a neighbour.