Vaillant Ecotec Combi Installation <br>Flue not connected to boiler with securing collar, just push-fitted<br>DIY vertical extension!<br>Condense pipe inserted into caste iron pipe after a hole was drilled.<br>Undersized gas pipe!<br>Elbow on flue not secured by collars!<br>No documentation left with owners.<br>They had lived with the installation for many months and thought something wasn't right, but had been reassured by the Polish plumbers that all was well!!!!!<br>I suggested they ask the plumbers to rectify their work and call me when they don't return.<br>Spotted the boiler after changing some radiator valves etc .
