Whining from a new Vailant Boiler

[Constructor57]

First a Hello from a new member.
I wondered if any of you experienced heating engineers have heard an intermittent whining noise coming from a new Vaillant ecotec plus 637 system boiler?

Fitted (complete new system) June '16, S.Plan -two CH zones and one HW (unistor 210), external by-pass & TF1 fitted, flushed and commissioned as per tech. Has run like a dream until November '16 when, once a day at aprox 1.30pm there is for couple of minutes a whining noise from the boiler. Since then the system has be re-flushed and the by-pass adjusted, but the noise persists.
Vaillant haven't answered my emails, so I thought I'd ask some real people, any pointers would be much appreciated.
I have a video from the clients phone, but I can't seem to attach the file.

Cheers
R.

 

[ShaunCorbs]

When does the noise happen when the boiler is on when it's fired etc ?

 

[Last Plumber]

Is this a noise like a trombone ?

 

[Constructor57]

Hi again, noise happens when boiler is running/fired then sound goes away as boiler shuts down. No nothing like a trombone, sounds quite high pitched. We thought there maybe a restriction but we have re flushed with care to no avail. The client is middle eastern and likes it blooming hot, so the system is peddle to the metal nearly all the time, shouldn't make a difference though.
R.

 

[ShaunCorbs]

How old is the boiler ?

 

[Constructor57]

Boiler was new in June '16
R.

 

[ShaunCorbs]

Boiler was new in June '16
R.

Get villant out should be under warrenty

 

[Last Plumber]

Under Warranty then ?

Get Vaillant eng out

My advice, make sure you are there for the argument !

Whenever I send MF Engineers to customer, I always ask customer to ring me at the first sign of a fob off, If I'm close enough I will go and meet the Engineer if not I will speak to them on the phone.

 

[Constructor57]

Okay will do, just thought it might be something simple or something we have overlooked.
Many thanks for taking the time to reply.
R.

 

[Scott_D]

Can you get the installer to look at it and ring vaillant
If not you may be charged