Original problem was my blower was kicking on for about 10 seconds without the furnace lighting up and sending heat with the blower then it would cut off about 10-20 minutes later the furnace and blower would run its normal heating. Changed the lennox for a hunter just right digital and had some trouble with the wiring. Now the furnace is working but seems to be only staying off for 20 minutes then back on and the blower is still kicking on for its 10 second no heat run. Can you help me?

The thermostat was probably not the problem. Check to be sure all return air ducts are not obstructed. Check to make sure air filter is clean. From the sound of this it might be a fan/high limit control if one is in this furnace. Please post model number of furnace.