My home furnace (Trane Model Number CCBB3684ACD0) is having a problem staying on. I followed the directions of turning off the Gas Switch, Turning down the Thermostat to the lowest Temp., and turning off thermostat. I wait for the recommended time (5 minutes, I've even went as long as not turning it back on over night, and when I turn it on and set the temp. to the desired level; it stays on for about 5 to 10 minutes and then if cuts off. Any ideas?