We have a three level house (unfinished basement) and two furnaces for each upper level. Ever since we have moved in (3 years ago) we have had a large disparity between the upstairs and downstairs despite putting each thermostat to the same tempature. In particular the master bedroom is commonly 20 degrees colder than the downstairs and 10 degress colder than the other rooms upstairs.

The vents have been checked and the blowers are working, we are at our wits end to figure out why it is so cold in the master bedroom compared to the rest of the house.

We live in a very cold area of the US and are really in need of some advice so we can start somewhere.

Hi,this is whisky4 look at my post JETLAG,about moving air with vent closure,thank,s

The thermostat control s the temperature where it is. Just turning the upstairs up could make the bed room warmer. Start by making sure the cold bedroom has both a heating vent and an air return. Next inspect any ducts you can access. Where are they, in the attic? Not the easiest place to work. Look for anything that doesn't look quite right. Make sure the joints are all tight. Repair them or seal any gaps with duct tape. If they are uninsulated metal ducts, cover them with fiberglass blankets.

If you don't find anything else, you might look at increasing the duct size to the cold bedroom.

Look at the furnace too. If it won't heat the upstairs even with the thermostat turned up, there may be something wrong. Does it have 2 different firing rates? Something could be wrong keeping it from firing properly. Could be something simple like the white wire from thermostat connected to W1 instead of W. Straightening things like that out could be easy if you have a manual. And difficult without one. Resetting the gas supply and fan speeds would be easy to mess up yourself. It is possible that if they weren't set up right, a professional could make a big improvement with a few adjustments. If you don't find something simple you can fix yourself, it might be a good idea to have one look at it.

As far as crawling around the attic and holding your hand over the joints of the ducts, you can do that a lot cheaper than a professional. Dirty insulation is a clue to an air leak. Post back with what you find. We can add details.