Boiler works intermittently

[vide]

My Vokera 20/70 boiler sometimes starts up and at other times will not. When it doesn't work it seems to try and ignite but cannot and makes horrible loud clanging noises. The boiler has also been very noisy for some time now and I have been told that it needs a new heat exchanger. This new problem is very recent and one enginer told me that the 3 metre flue had corroded so also needs changing. Obviously he recommended an complete new boiler and flue, at a price of £2300. Does anyone know if failure to ignite problem could be caused by the flue or is it more likely to be something else? The boiler is 11 years old.

Thanks

 

[gas4you]

If the flue has corroded then the engineer who spotted this should have condemned the boiler straight away as it is Immediately Dangerous

As for the ignition fault, I would be looking elsewhere other than the flue for this problem.

Although parts will still be available, the flue will not be.

 

[Agile]

Depending on exactly on how the flue has corroded, it could cause ignition problems.

In some cases it could cause the boiler to fill with unburnt gas and then explode and blow the case apart.

Boilers which have not been properly maintained can be very dangerous!

Tony