One thing I disagree on DIA is that punters do want a cheap but also top class job and to screw down the installer which is an impossible circle to square and I agree, they get exactly what they deserve.
Have to explain that one VC.
Intergas has no plate hx or diverter valve a bonus with any dirty system.
Unfortunately the skills level is sinking into the mire, and poor/shoddy workmanship is passed on to the notorious manufacturers.