DANGER OF THE WEEK AWARD

Bad Gas Fitters

While removing a boiler which was past its prime earlier this week we found the flue pictured in the photos below. The pitted and split aluminium tube on display is the inner tube which carries products of combustion (carbon monoxide and other nasties) out of the boiler and out of the house too. This flue however was not properly fastened to the top of the boiler so required NO effort to remove from the boiler or from the wall where it had the appearance of being firmly bedded in to the mortar.

The homeowner gave me some of the history and it appears that the boiler was installed prior to their purchase of the house.  If you look at the flue closely you can see two slits cut into the sides of the flue. The slits were probably cut because the flue pipe did not fit the elbow at the top of the boiler properly. The slits allowed the pipe to be pushed on easily. Unfortunately the slits also allow flue gas to escape.  The flue gases are what has caused the corrosion to start at the end of the tube. The corroded aluminium was so bad in areas that it had eaten completely through the tube.

So as the boiler to flue connection wasn’t safe in the first place (due to slits cut in the tube) the added escaping hot corrosive gases made the connection even worse. In turn the inner flue was leaking gas into the outer flue which is where fresh air is brought into the boiler to allow for correct combustion. As the fresh air supply was compromised the air/gas mix would have been incorrect which caused further issues due to the sooting up within the boiler.

So back to the history of the boiler. It was only a year or so ago when  a company was employed to do some fencing and for some reason one of the fencing blokes pulled the flue out of the wall. As I mentioned earlier the flue was not exactly a tight fit. So the homeowner called in a gas fitter who then refits the corroded and ill fitting flue without declaring the boiler as Immediately Dangerous (ID). The damaged flue should never have been refitted!

The gas fitter should have viewed a flue with such obvious signs of distress as an indication that something had gone wrong. The proper solution would have been to order up a new flue if still available or the boiler should have been replaced at that time.

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