I have a lennox 1994, 80% ignition, furnace. I am having a problem getting the burner to stay on until the house reaches the specified temperature. When the burner shuts down, the blower keeps running. In order to get the burner to kick on again, I have to fool with the thermostat such as turning it down below the actual temperature in the house, wait a few minutes and turn it back up, at which point the burner will kick back on for a few minutes but then it will shut off again and I have to go thhrough the process all over again.
What is the problem? Please help.