This morning I arrived and Shannon directed me to the two unit heaters that were not functioning. The first unit would not hold the pilot light and the thermocouple was tested and replaced. The unit heater returned to normal function after the repair. The second unit heater held a pilot light and function normally. It was not functioning today due to the gas having been turned off in the past and the pilot light needed relit. This unit heater is a reznor and is located in the bay door area of the shop. Both of the unit heaters today were checked for proper draft, heat exchanger health, fan motor bearing wear and each was cycled on and off after they were back in service. While they are in good condition I do recommend a carbon monoxide detector in the occupied areas due to the age of the equipment. Thank you, Jon Tech notes: new t-couple Dayton//S/N C7942790. Reznor, relit pilot, in the bay door area