I had a new heat pump system installed. The air handler makes a constant noise. The tech came out and said it was the transformer and it was normal. However, when he removed the transformer from the handler, about 2 inches away from the air handler, with the power was still on, the transformer stopped making the noise. However, when he just placed it inside the compartment within the air handler, and it was not screwed to the air handler, it started to make noise again. Tech suggests mounting the transformer outside the air handler.

two questions;

1. Why does the transformer stop making noise when it is removed from the air handler?

2. ok to mount the transformer outside the air handler?

Thanks for the help