Ariston eurocombi a23 noise

[jonwish]

Hi,
I have an ariston eurocombi a23 and it has just started making a low whining noise when the hot water or central heating is run.
It doesn't do it straight away but after a minute or two and then gradually gets louder.
It has also just started (last couple of days) making a low noise for a second when hot water tap is turned off.

I'm thinking maybe the pump? but as I don't know anything about combi boilers I'm not sure if it just for the central heating or hot water as well.

Any help would be very much appreciated.

Thanks

 

[Agile]

The pump is used on both CH and DHW water !

You can listen to the pump with a mechanical stethoscope!

But it might be a scaled up main heat exchanger!

Tony

 

[jonwish]

Thanks for the info.
If the heat exchanger is scaled up can I buy a product to descale it (inhibitor, cleaner, etc) or would it need replacing?

Thanks again for the help

 

[Agile]

They can be cleaned but few engineers bother.

Most prefer to replace it,

I do clean them myself.

Tony