The boilers were supplied with M+G plastic header kit, this was installed complete with it’s non-return valves.
As the M+G flue kit ended, it was converted to Dinak DWJ twin wall. This exited the plantroom and was installed with an inline drain.
The Dinak DWJ twin wall flue continued t0 exit to the outside and was then clipped to the building.
This was all completed within the allowed time frame and delivered on budget.