When to Replace Your Furnace (7 Warning Signs)

HVAC Logo IconBy Tom MoorAugust 23, 2024

As the temperature cools down, the leaves turn colors, and the footballs begin to fly, it’s a sure sign that the season is changing. Is your furnace ready to tackle another heating season? If your furnace was inefficient and broke down once or twice last season, odds are it may do the same – or worse – this winter.

In these cases, it’s probably time to consider furnace replacement. Replacing your furnace preemptively can lower energy costs, reduce repairs, and prevent a complete breakdown on one of the coldest days of the year. HVAC.com discusses common signs that indicate you may need to replace your furnace and provides DIY tips to keep your new system running smoothly for years to come.

Signs to Consider Replacing Your Furnace

1. Age

Like all HVAC equipment, your gas furnace has a shelf life, typically about 15-20 years. If your system is within this age range or older – and is highly inefficient – consider replacing it to avoid a breakdown. Electric furnaces, meanwhile, last about 20-30 years.

2. Frequent Repairs

While an occasional furnace repair is normal, frequent (2 or more per season) or costly repairs can signal it’s time for a new furnace.

3. High Energy Bills

If your monthly energy bills are significantly higher without any changes in system usage or weather conditions, your furnace could be losing efficiency. Older or malfunctioning furnaces often run longer and consume more energy to maintain the same level of comfort.

4. Strange Noises

Is your furnace keeping you up at night? Furnace noises like banging, clanking, or squealing can indicate serious mechanical issues that might require furnace replacement. While some of these noises can be repaired, it’s advisable to have a qualified HVAC technician inspect the issue and make the appropriate recommendation.

5. Uneven Heating

When you walk through your home, are some rooms colder or warmer than others? This could be caused by air duct leaks or tears, or it may indicate the furnace itself is struggling to maintain consistent heating due to age, malfunctioning equipment, or insufficient capacity.

6. Cracked Heat Exchanger

Due to the high cost of replacing a heat exchanger, it’s generally more cost-effective to replace the entire furnace if it develops a crack, unless your system is still under warranty and has no other issues.

7. Expensive Repairs

If furnace repair costs exceed $3,000, replacing the system might be more economical, though you should consider factors like one-time fixes, overall performance, and warranty status. As HVAC systems age, they often require more repairs, so compare the cost of repairs to the price of a new system.

Click here to view our HVAC repair vs. replace calculator to learn more.

Tips to Keep Your Furnace Running Efficiently

If you chose to buy a new furnace, it makes sense to protect your investment. Proper maintenance and care can keep your furnace operating for 15-20 years.

  • Change the air filter regularly. If you’re like many homeowners, it may be difficult to remember to replace your furnace filter regularly. Doing so, though, can improve efficiency, reduce energy costs, prevent breakdowns, and extend the life of your system. Although factors like the type of filter and its Minimum Efficiency Reporting Value (MERV) rating affect replacement intervals, most filters need to be replaced every 1-3 months. Consider checking the condition of your filter monthly.
  • Schedule regular maintenance. Your furnace should be professionally maintained once a year, typically in the fall before the arrival of cold weather. A furnace tune-up helps ensure your system is operating properly and can alert you to minor issues before they lead to more serious problems down the road.