If not, what could be the problem?

Question from user Pcj5026 at hvacadvice at reddit.com.

Answer:

In the mid Atlantic area, above freezing the last several days but the heat has been on. Fan starts and ends quietly but the buzzing – rattling noise starts shortly after kicking on and ends just before shutting down. Pushing or tapping on the unit seems to lessen the noise. Bolts are fastened, unit is level, nothing is noticeable in the fan area. Any help is much appreciated.

Answer from user Pcj5026 at hvacadvice at reddit.com.

newly installed bosch heat pump gets very loud is this normal