No heat out of ducts upstairs, why?

December 9th 2009
No heat out of ducts upstairs, why?

Q. We have heat ducts that seem to have no heat coming out in one of our upstairs bedrooms. What can we do to correct this problem?

North Delta

A. Because of the locations of the furnace in forced air systems, the furnace may not deliver heat to the furthest areas of the house, typically this will be the bedrooms or bathrooms over unheated areas such garages or car ports. If the basement ceiling is unfinished you can install in line duct booster fans controlled by a relay which turns the fan on when the furnace blower comes on, drawing warm air from the furnace plenum and delivering it to your cold rooms. Balancing of the furnace duct system can be done if all ducts are exposed under the subfloor by installing butterfly dampers. This should be done by a qualified heating contractor.

Shell Busey