Instructions

1

Verify that the thermostat is set to heat and that the setting is above the current room temperature. Turn the thermostat all the way up to see if the heater kicks on.
2

Look for the pilot light on a gas furnace to make sure it hasn't blown out and check that the gas valve is in the "On" position. Follow the manufacturer's instructions to relight the pilot if necessary.
3

Check the power switch for the blower unit. This is usually inside the cabinet with the heating unit. If the switch is on, check the circuit breaker and any secondary breaker boxes in the house.
4

Examine the blower motor and look for a reset switch. Pressing the switch resets the motor in the event an overload has occurred. In some cases it may take up to 30 minutes for the motor to cool enough to restart and you'll have to press the button again after cooling before the motor will work.
5

Turn the main power to the furnace off at the circuit box and look for a fuse in the power switch. If it's blown replace it with the recommended part in your user manual.
6

Return to the thermostat and check for loose wires, broken dials or stuck buttons. Reset a programmable thermostat to its default settings per the directions in the user manual.