There are several types of furnaces found in New Jersey homes, and the lifespans of each will vary. The estimated furnace lifespans below assume regular furnace repair and proper maintenance during the lifetime of the furnace.

• Typical lifespan of a natural gas furnace in NJ is 15-20 years
• Typical lifespan of an electric furnace in NJ is 20-30 years
• Typical lifespan of an oil furnace in NJ is 15-25 years
• Typical lifespan of a propane furnace in NJ is 15-20 years

You can repair an old furnace

Just because your furnace is near its lifespan does not mean you need to replace your furnace. Some issues can be addressed with simple furnace repair, especially if the unit has been properly maintained and cared for over the years.  

At DMG Mechanical the rule is to repair the furnace before replacing it. If a furnace repair can get you another season or two and there is no danger, or issues related to the increased degradation of the unit, its efficiency, or ability to function trouble free, and the furnace repair cost is reasonable, repairing an old furnace is usually the first option. 

Furnace lifespan can vary depending on type and where you live. Here in NJ there are three main furnace types

1. Natural Gas Furnace. This is the most common in NJ, making up >72% of the furnaces in NJ homes.

   Signs that you need a furnace repair or furnace replacement for a gas furnace are:

   1. Uneven heating and cold spots in the home
   2. Rising gas bills (beyond the normal NJ rate hikes)
   3. Frequent short cycling (furnace turns on and off often)
   4. Unusual noises like rattling or booming (expanding metal)
   5. Rust or corrosion around the venting or heat exchanger
   6. Burner flame color changes from normal blue to yellow or flickering flames.
2. Electric Furnaces. Second on the list are electric furnaces. n New Jersey, electric furnaces are less common than natural gas systems, but they do appear in certain types of dwellings and specific situations. Apartments or multi-unit buildings built in the 1970s-1990s with limited access to gas lines, all electric homes, or homes converted from oil or propane.
   
   Signs that your electric furnace needs repair or replacement,
   1. Rising electric bills
   2. Weak airflow
   3. Burning smell or electrical odor
   4. Frequent tripping of the electrical breaker

3. Oil furnace. The third most popular, the heating oil furnace has seen a decrease in popularity in NJ homes over the years and makes up <7% of the furnaces in NJ homes.

   Signs that your oil furnace needs repair or replacement,

   1. Soot buildup on walls, ceiling, or around the furnace itself.
   2. Increased fuel usage or needing more frequent oil deliveries
   3. Smoke or odor during operation
   4. Frequent burner or ignition failures even after repair
   5. Excessive corrosion on the tank or furnace body
4. Propane Furnace. Rounding out the bottom is the propane furnace. In NJ, this furnace type makes up <3% of all furnaces used in the garden state.

   Signs that your propane furnace needs repair or replacement,

   1. Uneven or insufficient heating throughout the home
   2. Rising propane costs due to the increased inefficiency of the furnace
   3. A yellow or flickering burner flame
   4. Unusual noises such as banging, rattling or popping
   5. Excess soot, dust or rust around the furnace and/or vent pipes.

Call a professional for furnace repairs

Furnaces are complex and no matter what the furnace type, they are harnessing dangerous and combustible materials. Always call a professional, trusted and trained HVAC company in NJ for any furnace repair or concern.