Maintaining Your HVAC Equipment

Keeping your heating, ventilating, and air conditioning (HVAC) equipment on a regular maintenance cycle is one of the least-expensive and easiest ways to reduce operating costs and avoid costly repairs. Your manufacturer's guide should recommend a program specific to the equipment, but certain areas should be checked regularly.

Heating Equipment

Furnace/Boiler Maintenance

You could save as much as 5% on energy costs by regularly checking and maintaining the efficiency of your boiler or furnace.

  • Frequently check the flue gas composition to determine combustion efficiency. The correct gas composition should be:
    CO2:  9% - 10% (gas-fired unit)
           11.5% - 12.8% (using #2 oil)
           13.0% - 13.8% (using #6 oil)
           No carbon monoxide
  • You should also examine the flue for hydrocarbon, carbon, and flash buildup
  • Measure the exhaust gas temperature. An abnormally high stack temperature (more than 150° above steam or water temperature) may indicate too much combustion air or dirty or deteriorated heat exchanger surfaces
  • Clean the heat exchanger surfaces often
  • Clean water handling equipment to eliminate lime and scale buildup
  • Keep furnace or boiler tubes free of soot, sludge, or flash
  • Replace automatic blowdown cycle on boilers as needed
  • Maintain insulation on boiler
  • Frequently calibrate controls
  • Check for water leaks
  • Check for air leaks in combustion chamber
  • Periodically check the fuel oil temperature
  • Keep economizer and preheaters clean
  • Keep fan lubricated per manufacturer's recommendations
  • Check fan blades
  • Check fan rotation and alignment

Electric Heaters

  • Calibrate controls often
  • Check heat transfer surfaces for obstructions and keep clean
  • Check fan rotation and alignment
  • Keep fan lubricated per manufacturer's recommendations
  • Clean fan blades

Infrared Heaters

  • Check and adjust beam direction when necessary
  • Dust reflectors with a soft cloth

Refrigeration Equipment and Chiller

  • Keep heat exchanger surfaces clean
  • Check refrigerant level. Add more if air bubbles are present in the sight glass, or if the refrigerant flow is turbulent
  • Check for leaks in the suction and discharge lines
  • Keep liquid lines and strainer free of clogs
  • Replace worn belts and check for correct tension and alignment
  • Check fan rotation and alignment
  • Keep fan lubricated per manufacturer's recommendations
  • Clean fan blades
  • Check compressor gauges for stable system pressure and normal discharge temperature
  • Check the compressor for leaks
  • Maintain air-cooled condensers
    • Tighten or replace the fan belt when necessary.
    • Lubricate the motor following the manufacturer's recommendations.
    • Check for leaks in refrigerant piping.
    • Keep the condenser fins straight/clean and free from obstruction.
  • Maintain evaporative condensers.
    • Repair leaks in the piping
    • Clean the coil regularly
    • Clean the air inlet screen
  • Maintain water-cooled condensers
    • Clean the condenser shell and tubes.
  • Maintain the cooling tower.
    • Keep free of lime or scale deposits
    • Clean heat exchanger surfaces
    • Adjust or replace V-belt as required
    • Clean the intake strainer
    • Check the overflow pipe clearance for proper water level
    • Check for an even water depth in the basin in the gravity-distributed tower
    • Clean and adjust the distributed and spray-filled nozzles
  • Maintain absorption equipment.
    • Clean the strainer and seal tank
  • Lubricate valves
  • Maintain the insulation
    • Look for signs of moisture and feel along the outside of ducts for hot or cold spots that may indicate missing insulation
    • Repair any torn or loose insulation
  • Maintain electronic air cleaners
  • Frequently clean the ionizing grounding place section
  • Replace filters as needed
  • Keep airways free from obstructions
  • Make sure dampers operate properly and move freely
  • Clean filters frequently and replace or adjust those that do not fit properly
  • Check fan rotation and alignment
  • Keep fan lubricated to manufacturer's recommendations
  • Clean fan blades
  • Periodically calibrate HVAC thermostats and control devices
  • Tighten and clean thermostat contacts
  • Keep thermostats away from heat- or cold-producing sources that could interfere with readings
  • Maintain pneumatic control systems according to manufacturer's recommendations