Check the electrical current going into the furnace. First, examine the furnace's 120-volt power cable and make sure it is not damaged or that it has not come loose from the outlet.
Replug loose cables and replace any damaged cables. If there is still no power, check the circuit breaker box for the furnace's circuit and turn it back on if it has been tripped.
Examine the thermostat temperature setting. Like all other heating appliances, the Williamson Tempo-O-Matic's thermostat needs setting a few degrees above room air temperature for the heater to function.
Turn the thermostat temperature up if it set too low.
Look at the oil supply. Examine all supply and return valves that provide the furnace with oil for combustion.
Ensure your oil tank is not empty and refill it required. If none of the above troubleshooting steps restore working order to your furnace, contact a Williamson repair professional to address the issue.