Minor ones.
1 Possible need for NRV to prevent reverse circs.
Never had this happen
2. No by-pass on combi.
Combi doesn't need it- although the system might.
3. Gas valve in way of pump.
How often do you need to get to the pump?
4. Jig struggle for 1 man.
Never had a problem - although I agree is it a bit flimsy
5. Need to fix spade connector for controls earth.
Yes that is a ball ache.
6. Pump head too low on system boiler.
Same for Bunnies et al.
7. No manual pressure gauge.
Never had a problem - boiler works down to 0 and dry firing isn't a problem.
8. Have to buy pipe cover.
Same for any other company.
9. Lime fighter or water softener required.
Same for any other company.
10. HW 'slug'.
Not if you set the temperature correctly for heating.
11. Trap not screwed or bayonet.
Why is this a problem? It won;'t come off with the front case on unless you REALLY force it.
12. CO2 'L' figures always out.
Only had this on a few. Certainly no more than any one else's. WB for example .
Major ones
13. No cable clamps, wires pass through grommet knockout which leaves hole compromising case air tightness,
Most of mine only need the one extra cable so the rubber grommet is fine, although I do by glands for other control installations so not a problem.
14. FGA port useless with some side flue installs
True - but do all other companies have test points off the turret elbow?
15. Flue fouls F/R connections on OV so have to use offset flue which leaves joint in wall. Engagement minimal on M&G flues with no lock, screw or band to secure, a major headache on long or vertical systems.
That first connection to the turret could be better - but can't say it has impeded any installations though.
P.S. I was more worried about thread hijacking than secrecy.... you should join the CC - its quite fun at times.