OK i know i should leave it but i thought i would put my two cents in aswell!!
First off it seems that a few people have forgotten what NCS, AR, and ID mean. (not mentioning names)
NCS - the installation met previous regulations but does not now meet the current regulations in force but the installation is working safely.
AR - the installation does not meet current regulations in force and
may present at danger to person on property in the future.
ID - the installation does not meet current regulations in force and poses an immediate danger to persons or property.
Now taking into account that the installation has:
less than 600mm vertical flue between appliance and the first bend - NCS
no purpose provided ventilation - NCS
incorrect use of flue material - NCS
In legal terms, provided that the appliance has passed all relevant safety checks (flue flow/ splillage etc), then the engineer would be within his rights to deem the installation as NCS but...........
taking into account the wording of what an AR situation is then the most sensible option is to classify the installation as AR as we all know that a setup of this nature will be highly vulnerable to the unknown factors eg flue inversion etc. It may well pass on the day but it could well pose a danger tomorrow.
NOTE TO HOMEOWNER: This appliance needs to be tested by an RGI ASAP!!! There are many other factors that we on here cannot see and assess (are there extracts in the room or interconnecting rooms/ ceiling fans/ is it a compartment.. the list goes on) but as you can tell, from just one picture, most engineers aren't too happy with the installation and have deemed it to pose a potential risk to either you or your tenants.
Rant over sorry if my wording is off on some points but its late!!
i think i feel a Bamber apology is required ( only from him because he seems to be the only one who cannot discuss anything but has to try to impose an arrogant bullish attitude)
I could not agree more!!!!