I recently replaced the entire CH system in my two-storey house with a new gas combi boiler, rads, everything. The old freestanding gas boiler in the downstairs kitchen was connected to a flue liner sharing a coal fire flue, exiting via standard chimney on the roof apex, with no cowl.
The installer left a hole in the wall after removal of the boiler, which was plastered over. We are now getting staining in this area, which a colleague thinks is due to the flue not being capped or cowled on the roof.
Questions:-
What happening to the rainwater previously, as no staining?
Is rainwater ingress now likely to be the cause of staining?
Should the Gas Safe installer have cowled or capped the old flue to follow any relevant regulations?
All comments appreciated.
