How to Maintain Your Gas Furnace

Gas furnaces provide many years of reliable performance with preventive maintenance and routine inspections. You should be able to handle many maintenance tasks on your own, but you should contact a qualified gas contractor to inspect your home heating system at least once per year or according to the intervals recommended by the manufacturer.

Follow These Steps For Routine Maintenance:

  • Note About Safety — Turn the furnace off and shut down electricity to the unit on the home’s circuit breaker panel before replacing fan belts, changing filters and inspecting the unit.
  • Make sure the fan compartment door is closed and clean or change the filters every 90 days. In mos units, a small clip holds the filter in place inside the blower compartment or near it.
  • When changing the filters, inspect the fan belt and replace it if there are any signs of excessive wear or cracks.
  • Clean out any pet hair, lint or dust that accumulates in the air returns and vents and make sure furniture and other objects are not blocking airflow through them.
  • Inspect the vent system and chimney on an annual basis to look for damage, corrosion or foreign objects that may be blocking the flue or chimney as well as to verify the pipe connection is secure.
  • Clear away all objects from all sides of the furnace. Do not lean items against the side of the unit. Never keep flammable products in the same room with the furnace.
  • Always hire a qualified gas contractor if you want to enclose the furnace.
  • A couple drops of SAE 20 oil should be applied to all oiling points once a year before the winter. Be careful not to apply too much oil.

Signs of Trouble

In most cases, a malfunctioning furnace will exhibit one or more warning signs.

Here are the most common signs of trouble:

  • The pilot light goes out frequently.
  • Delays before ignition. You may have a high efficiency furnace with a built-in delay, so read the owner’s manual.
  • A flame that wavers or is yellow in color.
  • Black, brown or white streaks indicating excessive corrosion or soot on the vents or the furnace.
  • The furnace generates too much heat or fails to generate enough heat.
  • The furnace emits a foul smell that resembles the smell of rotten eggs or makes the eyes sting.
  • Anyone in the household has signs of carbon monoxide poisoning, which include lethargy, headaches, nausea or flu-like symptoms.
  • Burn marks near an opening or the furnace door that indicate flames have escaped from inside the furnace.

What to do When You Smell Gas

If you think your furnace has a gas leak or you smell gas, contact your natural gas supplier on the emergency phone line. Write down the contact number ahead of time and keep it in a convenient place so you can respond as quickly as possible.

What to do When the Pilot Light Goes Out

Many modern appliances will shut down automatically if the pilot light goes out. Locate the manufacturer’s instructions printed on a metal plate somewhere near the gas controls or the furnace burner and follow them to relight the pilot if it goes out. If you cannot get the pilot to light, turn the gas supply valve off and contact a qualified gas contractor to look at it for you.

Note: Many new models lack a pilot light. Read your owner’s manual to determine if your unit has one.

Furnace Maintenance Tips