I'd like to preface this post with the fact that I'm a complete diy amateur. I may say stupid things, or things that make no sense. Please feel free to correct me as I'm always open to learn. So, ...
I have a new, 3-year old, high-efficiency furnace in my home. Last year it started making a slight whining noise that was audible during the very first stage, before the blower motor started. No ...