High Pitched Evohome BDR91

Hello,

I received my Evohome today to replace my nest and I have wired it up, heating seems to be working and the controller is correctly switching the boiler on/off. The issue I have is that there seems to be a high pitch coming from the BDR91 is that normal? I have included a picture of my wiring.

IMG_1154.jpg

IMG_1160.jpg

Is the wiring okay and what do you think is causing the high pitch?

Thanks in advance
Sam

Attached Images

• IMG_1154.jpg (87.0 KB)
• IMG_1160.jpg (85.7 KB)