Hi @user48800. I’d highly suggest disconnecting the Doorbell from the circuit and following up with our support team to safely review the wiring. We take your safety very seriously, and there should not be a burning smell when the Doorbell Pro 2 is installed. Please give our support team a call at one of the numbers available here. The support agent you speak with may ask for pictures of the chime kit and transformer. If you are outside of the US, please visit here to see how to contact support.