By Darryl Bowens

Harsh conditions on the rooftops of most buildings can lead to many potential problems with the HVAC equipment that is located up there. However, there is a way to ensure that your customers' equipment lives up to it's potential, and serves them well — annual maintenance.

At Cropp-Metcalfe, we perform scheduled, routine maintenance on all of our commercial rooftop customers' equipment. We've developed a comprehensive checklist for our technicians to follow, to ensure that we "leave no stone unturned."

Thorough maintenance ensures that the rooftop unit is performing at it's peak, and it gives your technician a good opportunity to identify any potential problem areas —whether something needs to be repaired or replaced.

The following is the operational maintenance inspection checklist for packaged rooftop units that we use at Cropp-Metcalfe.

Each of our trained technicians must follow through on each of these 30 steps, which results in a thorough, detailed inspection report for our customers.

Checklist — Packaged Rooftop Units
  • Check the condition of the air filters. Change them as needed.
  • Check and confirm that the compressor is using the correct volts/amps.
  • Check and confirm that the condenser fan is using the correct volts/amps.
  • Check and confirm that the condition of the starters and contactors are in working order.
  • Check and confirm that there is a proper refrigerant charge.
  • Check and confirm that the unit is achieving proper operating temperatures.
  • Check and confirm the condition of the site-glass.
  • Check and confirm that there is a proper amount of oil. Change the oil, where applicable.
  • Check and confirm that the condition of the belts are in proper working order. Change the belts as needed.
  • Check and confirm correct operation of all safeties and limit switches.
  • Check and confirm super heat.
  • Check and confirm the hot gas bypass and controls are working properly.
  • Check and confirm the operation of unloaders, where applicable.
  • Check, and tighten, all electrical connections.
  • Lubricate motor bearing, where applicable.
  • Check the condition of the condenser coil, and clean it as needed.
  • Check the system for any operating noises that may sound out of the ordinary.
  • Check and confirm the condition of the condensate drain and drain line, and clean both as needed.
  • Make a visual inspection for any signs of leaks, whether it be refrigerant, water, gas, or air.
  • Check and confirm that the proper power supply is being used.
  • Check and confirm correct operation of thermostats and other controls.
  • Check and confirm correct operation of all accessories, such as humidifiers and air cleaners.
  • Check and confirm the status of the roofcurbs.
  • Check the unit's cabinet for any signs of deterioration.
  • Check and confirm that the condition of the evaporator fan motor is in proper working order.
  • Check and confirm that the condition of the heat exchangers is still good.
  • Check and confirm proper operation of economizers and outside air dampers.
  • Check and confirm proper operation of low ambient controls.
  • Check and confirm proper operation of pilot, ignition, and burner controls.
  • Provide the customer with a detailed report on all of the finding from this checklist.
Operation Maintenance Inspection
Thorough, routine maintenance on your customers' rooftop units will ensure that the performance of the building's HVAC system is in peak condition year-round.

By following this comprehensive checklist, your technicians will be giving your customers the piece of mind that their rooftop HVAC system will survive the elements and last a long time.

Darryl Bowens is the commercial service manager for Cropp-Metcalfe, one of the largest residential and light commercial heating, air conditioning, and plumbing contractors in the Washington Metropolitan area. To reach him, e-mail dbowens@croppmetcalfe.com.