How do you know if your furnace is dying?

Author: Kian Yost  |  Last update: Sunday, June 8, 2025

Signs your furnace is going out include inconsistent heating, strange noises, frequent short cycling, a yellow burner flame, and higher heating bills. If it's over 15-20 years old or requires frequent repairs, it may be time for a replacement.

How do I know if my furnace needs replacing?

Common warning signs of an ailing furnace are frequent repairs, rising energy bills despite a constant temperature, unexplained noises (such as popping, banging or screeching), and dust or soot build-up around registers. A furnace lasts approximately 15 years, depending on maintenance and other factors.

How do you tell if your furnace died?

Below are five of the major signs to call us for assistance:
  1. Loud operation. Furnaces make some noise when they run, but the sound of the burners and the fans isn't distracting and you're used to it as part of the sound of winter. ...
  2. Uneven heating. ...
  3. Short-cycling. ...
  4. High heating bills. ...
  5. You can't seem to get warm enough.

How long does a furnace usually last?

The Average Furnace Lifespan

A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.

What fails first on a furnace?

If the flame sensor fails, your furnace may not be able to start or may shut down shortly after starting. Common causes of flame sensor failure include corrosion, dirt buildup, or a broken wire. The gas valve controls the flow of gas to the furnace. If the gas valve fails, your furnace won't be able to produce heat.

Signs Your Furnace is Dying

What is the most common furnace failure?

One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn't working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.

How much is a new furnace?

Ask twenty professional HVAC contractors the question, “How Much Does A New Furnace Cost?” and you'll probably get the same answer... “It depends.” On average, the cost of a new furnace can range from $2,000 - $14,2001. However, factors like furnace efficiency, type, size, and much more can impact this range.

How do you know when your furnace is about to go out?

Signs Your Furnace is Going Out
  • Increasing illnesses.
  • High furnace age.
  • High and unexplained utility bills.
  • Sudden troublesome noises.
  • Pilot flame color.
  • Dry air.
  • Soot.
  • Frequent repairs.

What time of year is cheapest to replace furnace?

For people taking a proactive approach, doing a furnace replacement during the “shoulder seasons” of spring and autumn may offer lower prices, shorter lead times, and a better selection of products and service appointment availability.

Is it worth fixing a 20 year old furnace?

Repair: If your furnace system is less than 15 years old and the cost of repair is less than half the cost of replacement. Replace: If your furnace system is more than 15 years old and requires a costly repair to maintain efficiency.

Should I hear my furnace running?

While all furnaces generate some ambient noise, they run quiet enough not to be disruptive most of the time. However, loud buzzing or humming can indicate various mechanical or electrical problems, either when the furnace starts up or throughout its operation.

What happens when your furnace goes out?

If you have any drafts in areas in your home or poorly insulated windows, a malfunctioning furnace can quickly lead to a vent pipe blowing warm air into the atmosphere and cold air descending in through the cracks and crevices. This, of course, is bad for you.

How do you know if your furnace is not working properly?

If your furnace isn't working, check that the thermostat is set to heat and that the temperature is set at least 5 degrees higher than the current room temperature. If the display is blank, the batteries may be dead, which prevents the thermostat from operating your system.

How do you know when it's time for a new furnace?

A furnace will often become louder or make unfamiliar noises before it breaks down. If you hear new or changing sounds from your furnace – like rattling, humming, whirring or buzzing – it can indicate that your furnace needs replaced or repaired.

How to tell if your furnace needs cleaning?

Let's look at some of the signs that furnace cleaning should be performed sooner rather than later:
  1. High energy bills.
  2. Reduced heating efficiency.
  3. Unusual noises/frequent cycling.
  4. Funny smells.
  5. Increased allergies or respiratory issues.
  6. Dirt, debris, or clogged filters.
  7. Yellow furnace pilot light flame.

How much did it cost to replace a furnace?

Electric furnace installation tends to be the least expensive, ranging between $3,000 and $7,000, according to HomeAdvisor. Installing a natural gas furnace falls in the range of $3,800 to $10,000, and an oil furnace ranges $6,750 to $10,0000.

How long does it take a professional to replace a furnace?

4-8 hours. Furnace installation in a residential home usually takes 4-8 hours, depending on the complexity of the job. Additional time may need to be added to account for ductwork, electrical, or gas line modifications to properly match the new equipment.

How much should I spend on a new furnace?

To give you some idea on what to expect, a new furnace may cost you anywhere from $3,000 to $7,000.

How do you know if your furnace died?

The pilot light in a well-functioning furnace should be blue and vibrant. Pale or weak flames indicate a problem with the amount of gas burning. If your pilot light is wavy or flickering, the gas may not be thoroughly burning. This could indicate a leak, inefficiency, or another issue.

How much does a new furnace cost?

You should expect to spend between $3,800 and $12,00 on a new furnace, including both the unit and installation costs. Factors influencing the price include the type of furnace (gas, electric, or oil), the unit's efficiency rating, and the complexity of the installation.

How to tell if a furnace needs replacing?

8 Telltale Signs Its Time To Replace Your Furnace
  1. The Age of Your System. ...
  2. Rising Energy Bills. ...
  3. Excessive Dust, Dirt, Soot or Rust Particles. ...
  4. Home Humidity Problems. ...
  5. Rooms are Heating Unevenly. ...
  6. Furnace Becomes Unusually Noisy or Develops Rattles, Buzzes or Hums. ...
  7. Furnace Has Visible Signs of Rust or Cracks in or Around System.

Does homeowners insurance cover furnaces?

Your base homeowners policy will cover many types of damage to your furnace. An extra endorsement known as Equipment Breakdown Coverage (EBC) will give you additional coverage for certain types of mechanical or electrical failure.

Is it cheaper to replace furnace and AC together?

You'll be happy to hear that while your exact cost savings will vary based on the systems that you choose to install, we've estimated that bundling furnace and AC installations will save you an average of $2,000 and $5,000.

How much is a furnace for a 1500 square foot house?

Gas Furnace: $3,000 – $6,000. Electric Furnace: $2,500 – $5,000.

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