Gas safety week is 14-20. September but for us every week is about gas safety. We’ve just visited a property in Whitley Bay to service a boiler. On removing the boiler air tight cover we found the boiler heavily stained with rusty water and wondered what was happening.

Damage to the inside of a boiler like this is a great cause for concern as this will dramatically shorten the life of the boiler and could result in damage to other internal components such as the fan and gas valve.

Before servicing the boiler the source of the leak needs to be found and rectified. After a closer examination of the flue it was discovered that a similar rust pattern is evident and this leads one to think that products of combustion, which are high in water vapour, has been escaping and eating away at the seals in the flue.

This means that the flue has failed (in its job to transport all of the combustion products outside) and is now unsafe.

Products of combustion entering the home is unsafe because they could contain carbon monoxide which is a deadly gas and if left to continue would kill all of the occupants in the house.

It looked like the boiler’s flue has not been fitted square to the wall probably because the boiler had replaced an older boiler which had a different flue position and which had not been adjusted to fit the dimensions of the new boiler.

This fault was created at the time of installing the boiler and is not related to its warranty, service or age. The company responsible (British Gas) for fitting the boiler need to rectify the fault and make it safe again.

Your safety is always of primary concern, no matter who’s fault it is, no one should be left with an unsafe situation. We completed a Gas Safety Warning Record and passed responsibility on to the home owner who agreed, in writing, to take over the problem.

Hopefully British Gas will recognise the fault and rectify it quickly.

****** Update 20/07/2020******

British Gas have attended the problem and determined that the seals have perished. They said this was a common problem on the earlier Worcester boilers but they were happy to replace the flue system free of charge.

I spoke to Worcester about their flues and they confirmed that there was NO problem with the seals and that the flue must have been fitted with an incorrect drainage angle at the time of installation.

If a flue is not fitted with a back fall of 53mm per 1000mm the condensate fluid (carbonic acid) will collect in the seal recesses and destroy the seals.