It reached its high limit temperature, shut down the flame until the blower
cooled it down, then restarted. Once the room temperature was raised it was
able to satisfy the thermostat before reaching its high temperature limit in
future cycles



"Rod Dahl" wrote in message
...
I have a 4 year old Lennox gas forced air furnace. When I get up in the
morning and turn the thermostat up from say 68 degrees to 72 degrees, the
furnace fires up and heats the house up to 70 degrees and shuts off. The
digital thermostat still displays the icon calling for heat, but the
furnace stays off for 5 or 10 minutes and then starts up again and finishes
heating the house to 72. After that, it maintains the temperature
perfectly. It seems the thermostat is working properly because it shows
that it's calling for heat. Why would the furnace shut off prematurely
like that?
Thanks