We had a new house air conditioner with heat pump put in about 2 months ago.
As the temps have dipped here in Mississippi we turned on the heat.
There is a smell when it is on that smells like sauerkraut. It sounds strange but 3 different people other than us has also said sauerkraut.
Can anyone tell me what is wrong and why the smell?
Thanks in advance.

Well I doupt if it is the durty socks syndrom because the unit is not that old. Call the contractor that put the unit in and have them figure it out. You should still be under warranty.