Baxi Solo 15HE - whistles after 5 mins from starting

[northstander79]

I have a Baxi Solo 15HE boiler that is just under 1 year old. When the heating is turned on from cold, after about 5 minutes the bolier begins to whistle for 2-3 minutes and will then go quiet again(still with the bolier running). This starting happening all of a sudden but doen't seem to be getting any worse - its just annoying when it does it every time the boiler is started.

The boiler doesn't whistle when the heating AND hot water is on - if you run both together for 5 mins and then turn off the hot water, the whistling noise will happen.

I've had the people who installed the bolier out to it and can't find a problem - so have contacted Baxi.

I just wondered if anyone had any ideas as to what it could be?

 

[shawd]

Sounds that come from that area are more often due to muck in the heat exchanger, even if its only a year old, I bet the noise was not their on day one,