New noise on Potterton boiler

[bathjobby]

I have a 19 year old Potterton Netaheat Profile 50e boiler that is working fine and was quiet. Last few days I have had a constant new load noise from it. It starts as soon as the boiler is called upon (fan starts), even before ignition and continues until the boiler switches off. The noise doesn't sound mechanical it sounds like what you may get with a very strong wind blowing into the exhaust.
I'm guessing it is the fan on its way out after all these years but can't reconcile the type of noise with a failing fan (was expecting mechanical bearing failure noise or something).
Any of you guys out there experienced this type of noise ? If so, is it associated with a failing fan or likely to be something else ?

Many thanks in advance.

 

[superdupergasman]

Inner flue may have rotted away causing the boiler to hunt for air.

Flue blacking pannel could have become loose and boiler is blowing out air.

Get it checked out pronto...this boiler is a positive pressure and can/will blow fumes out the case into living space if certain faults develop.

 

[Agile]

The fan is the only moving part in your boiler so it seems most likely to be the cause.

Be aware that your boiler is a potentially very dangerous model which kills people so you should only have a competent CORGI open the boiler up to check or replace the fan.

Tony

 

[bathjobby]

Thanks guys, I'm well aware of the positive pressure issue with this boiler. From your suggestions it sounds like super,etc is close to the possible cause as it is definitely a 'wind type' noise and not mechanical. Thanks both again.