The Importance of Annual Boiler Servicing

The picture shows a flue turret off a high efficiency boiler which is only about eight years old. The red arrow indicates a hole in the metal alloy inner duct just above where it connects to the boiler.This is the duct which conveys the products of combustion to outside whilst the outer duct conveys fresh air into the boiler for combustion.
We had been engaged to carry out annual servicing on this boiler and eight others the same as it,

in a block of flats for a commercial client. Prior to taking the case off this boiler we took a 'before' reading with our flue gas analyser and immediately picked up high levels of CO, at over 7000PPM {parts per million}. Luckily this deadly gas was being conveyed to outside atmosphere but had a case seal failed on the boiler the consequences could have been deadly.
The boiler was producing this CO because the flue gases from the burner were mixing with the fresh air being drawn through the air duct for combustion via the hole in the inner duct. The hole has been caused by the corrosive nature of condensate present in the flue gas.
Our client who we have an excellent and long standing working relationship with, demands the highest levels of gas safety in their properties. As such we went straight ahead and replaced this flue and got the boiler working safely again. As a result of this incident the flues on all of the other boilers in these flats have been renewed as a matter of precautionary / preventive maintenance.
These boilers have been meticulously maintained and serviced every year. I know this because it is us who have done it. The moral of the story is always keep up with your servicing. On many occasions everything may be working safely and efficiently and there is little to do. Many homeowners and landlords could almost be excused for thinking "Why am I paying for this?" Well it's incidents like this, on well maintained boilers, that prove how invaluable annual servicing is. It also shows the importance of using flue gas analysers. If you have any questions or require advice on servicing matters please don't hesitate to contact me.