Flue inspection hatches

Since the regulations changed flue inspection hatches are required to be fitted to allow inspection of the flue . Here’s why . We called to a fault on a boiler, repaired the fault and on inspecting the flue, we couldn’t . But we could smell fumes and this was confirmed with our flue analyser . We set about cutting out the ceiling where the flue joints were, can you see the problem ! Boiler service, Dunstable