I have a single furnace for both levels of our home. It is definitely colder in the basement and when we try to raise the downstairs temp by turning up the thermostat (located upstairs) it gets incredibly hot upstairs. Any ideas? Do I need to add a new furnace or can I relocate the thermostat downsters?
Thanks!
jumpercalder

Sounds like maybe there not enough supply vents in the downstairs,or maybe was designed wrong,is the furnace big enough ?when furnace was installed,was it intended for both floors?do you have a return for the lower level? A lot of questions need to be answered

Close upstairs registers all a about 50 - 70% and be sure all the lower floor registers are open and non restrictive. Also be sure there are no dampers closed in basement ductwork.

Make sure all the vents are clear. Also try insulating any basement areas possible. If there are doors, add good quality weather stripping. With windows, try to cover them with a couple layers of clear plastic sheeting. That along with proper vent adjustments should do the trick.