Maintaining your natural gas furnace or boiler

Maintaining your natural gas furnace or boiler

Maintaining your natural gas furnace or boiler

Regularly maintaining your natural gas heating system not only helps keep it working safely and efficiently but also helps promote good air quality in your home.

Have it serviced by a professional

Schedule regular inspections, cleaning and maintenance with a licensed gas contractor. Your owner’s manual should tell you how often you should have your equipment serviced and what it should include. Technical Safety BC generally recommends annual servicing and provides checklists of what to look for in a natural gas furnace, boiler or water heater service.

What should a furnace service include? 

In general, your contractor should: 

  • check the operation of safety limit controls, temperature set points, thermostat, blower, pressure switches, ignition and venting system 
  • remove and clean the blower
  • inspect the heat exchanger and burner 
  • in older models only: lubricate the blower and motor bearings, and remove and clean the burner

What should a boiler service include?

In general, your contractor should:

  • check the operation of safety limit controls, pressure relief valve, water pressure, venting system, temperature set points and radiant floor temperature control device
  • in older models only: lubricate the circulating pump, and remove and clean the burners

After the service, ask your gas contractor for a copy of their completed checklist. 

Furnace safety tips

  • Check your furnace filter at least every three months and replace or clean it if it’s dirty. It should be located near the blower fan and may be held in place by a clip. If there are pets or smokers in the home, you may need to check the filter more often. A clean filter helps your furnace run more efficiently and helps maintain the air quality in your home.
  • While changing the furnace filter, you may wish to inspect the furnace’s fan belt. If you see cracks or signs of wear, it may be time to have it replaced. Safety tip: shut off the electricity at the furnace switch and at the circuit breaker panel before inspecting or changing filters or fan belts. 
  • If your furnace motor has oiling points, apply a drop or two of SAE 20 non-detergent oil every heating season (avoid over-oiling).
  • Keep the area around the furnace clear. Don't store items against the furnace or keep flammable items in the furnace room, such as laundry, papers, boxes, solvents, propane cylinders or gasoline-powered equipment.
  • Keep air supply and return vents throughout your home clear of obstructions like furniture, lint, dust debris, leaves or pet hair.
  • Check the chimney and appliance vent system at least once a year to ensure the pipe is connected securely, there are no signs of corrosion or damage and nothing has fallen into the base of the chimney or into the flue.

When to call a professional

If you notice these signs of trouble with your natural gas furnace or boiler, it may be time to call a licensed gas contractor for repairs or replacement:  

  • any continuous or intermittent odour, such as the “rotten egg” smell of natural gas or a sharp odour that may cause eyes to sting
  • symptoms of the presence of carbon monoxide: nausea, headaches, lethargy or other flu-like symptoms
  • frequent pilot light outages (many newer gas furnaces do not have a standing pilot light – check your manual)
  • delayed ignition (mid- and high-efficiency furnaces have an intentional delay – check your manual)
  • a yellow or wavering flame
  • excessive soot or corrosion on the appliance or vent system (white, brown or black streaks)
  • too much or too little heat
  • indications that the flame has “rolled out” of the furnace – scorch marks by the door or other opening