Customer explained how furnace kept running and was 85F in home. Thermostat was set to off upon arrival. Turned it on to test operation. It did turn on and off correctly, but there is other concerns. Thermostat does not appear to be working correctly. It read 51F, my thermometer read 64F. Also found blower motor starter failing as well as blower motor. The changes of there being any other issues with system other than what has been found is possible. Due to overall condition of equipment and also with system be 30 years old, replacement is highly encouraged over repairs. Provided estimates to customer.