I just moved into the home and it has a Nordyne Miller furnace that seems to be running fine however there is always a low humming noise emitting from the furnace... from what I have read it may be a transformer... is this normal for it to be constant?. the model is MGHA075ABFC01

Many transformers make that noise. It is because they are cheap made and the plates in the transformer vibrate. The noise will cause no harm.

Thank you for your quick respose... one less thing to worry about is always good!!

No problem