When to Replace a Furnace or Repair It!

When to Replace a Furnace or repair it

πŸ”₯ When to Replace a Furnace or Repair It!

I’m going to start this article by letting you know that you will learn our recommendations for when to repair a furnace or replace it.

Still, I want to provide a disclaimer that every person should weigh our recommendations based on their risk tolerance and personal finances.

Among others, the main variables we’re going to analyze are the furnace’s age, the cost of the repairs, and the time it might take to get the parts.

No matter whether you choose to repair or replace your furnace, you should make sure to get at least two professional HVAC contractors to give you their opinion on what to do.

πŸ”₯ How Do You Know When It’s Time to Consider Getting a New Furnace?

cold woman shopping for a replacement furnace

The first thing you should always consider when deciding to repair or replace your furnace is its age, but keep in mind that age is relative to the amount you use it.

It’s like putting miles on a car. The hotter you keep the temperature setting in your house, the more miles you will put on your furnace.

With that said, the simple way to look at furnace age is that if your furnace is twelve years old or younger, you’ve changed your filter semi-regularly, and you haven’t driven it like it’s stolen, then your best bet is to repair it.

On top of that, after you repair it, you should definitely have a professional HVAC technician perform annual maintenance to ensure that you have an efficient heating system for years to come. 

πŸ”₯ The Warning Signs That Furnace Replacement is Coming.

There are 7 main warning signs that it might be time to replace your furnace.

Your old furnace is more than sixteen years old, your energy bills have been increasing, you hear strange noises, you need to adjust the thermostat more, and your furnace repair costs are increasing.

πŸ›‘ Warning Signs:

  1. Old furnace
  2. Strange noises
  3. Increasing energy bills
  4. The thermostat isn’t keeping up
  5. Frequent repairs
  6. Problems with the furnace burners
  7. Poor indoor air quality

1. Your HVAC System is 16-20 Years Old:

Old Furnace

The national average for furnace ages is sixteen to twenty years old, so naturally, you might need to replace your furnace if yours is older than that.

With that said, I’ve seen gas furnaces over thirty years old that have a great heat exchanger and that I would still consider an efficient furnace.

❌ When to Repair: Only minor repairs are needed with a low monthly energy bill.

βœ… When to Replace: It’s time to replace your furnace if costly repairs or frequent repairs are needed.

2. Your Old Furnace is Making Strange Noises

furnace making strange noises

Does your furnace squeal, squeak, bang, clank, or make loud noises?

You can still have a working furnace, but if the blower motor, gas valve, heat exchanger, or transformer start making weird noises, then your furnace’s age is starting to show.

One of the biggest concerns is if the heat exchanger has issues, which could mean cracks or holes in it and cause carbon monoxide poisoning to you and your family.

Note: if you need to replace your furnace, you should have proper maintenance performed yearly.

This will increase the typical lifespan of any HVAC system.

❌ When to Repair: Furnace repair is the way if the noises are caused by low-cost replacement parts.

βœ… When to Replace: It’s time to replace your furnace if you have multiple different noises caused by a motor failure or a heat exchanger failure.

3. Your Furnace is Causing Increased Energy Bills

gas bill

Maintaining your furnace every year will not only increase the expected lifespan of your furnace but will also ensure you have an efficient furnace for years to come.

Now, regular maintenance will only take you so far.

Eventually, you will end up with things like an unbalanced motor and unsecured ductwork, and it won’t distribute heat evenly.

Most furnaces with these symptoms start to drive up your utility bills and eventually lead to needing a new system.

❌ When to Repair: If your heating bills are still low and furnace replacement isn’t in your budget.

βœ… When to Replace: It’s time to replace your furnace if the repair bills are increasing as fast as your energy bills.

4. You’re Constantly Adjusting Your Thermostat to Feel More Comfortable.

Woman hot due to faulty thermostat

If this is a new issue, then it’s most likely time to replace your furnace.

If you’ve always had this issue, then a new furnace alone won’t solve the problem, as you most likely need to have your air distribution system (ductwork) inspected and re-designed.

If your furnace is over fifteen years old, you would still want to replace it, most likely with a furnace with a variable-speed ECM blower motor.

These motors are better suited to handle improperly designed duct systems.

❌ When to Repair: If the repair cost to replace your blower motor or thermostat is less than 30% of the furnace replacement cost.

βœ… When to Replace: It’s time to replace your furnace if it’s more than fifteen years old and you’ve always had a problem with air distribution.

5. Furnace Repairs are Needed Every Year

Phyxter tech repairing a two stage Furnace

If your gas furnace had a motor failure last year, was blowing cold air the year before, and it can’t maintain efficiency, your bills are skyrocketing this year.

It’s definitely time to upgrade to a high-efficiency furnace.

❌ When to Repair: Only minor repairs are needed, and the parts are readily available.

βœ… When to Replace: It’s time to replace your furnace because parts become harder to find and more expensive as your natural gas furnace ages. Most furnaces need the majority of their repairs within the last two years of operation.

6. Your Natural Gas Furnace’s Burner Flame is Yellow Instead of Blue

Yellow Furnace Burner Flame

Every natural gas furnace or propane furnace can run the risk of creating poisonous carbon monoxide.

A tell-tale sign of this is a yellow flame. Some other signs include:

  • Streaks of soot around the furnace
  • Excess moisture found throughout the house on cold surfaces
  • Excessive rust on the furnace around the flue pipes

If you want to ensure your furnace isn’t emitting carbon monoxide in your flue gases, you’ll want to hire a professional HVAC technician to perform a combustion analysis.

I recommend having this performed every year.

You should also have carbon monoxide detectors on every floor of your home, and be sure to change the batteries every year.

πŸ›‘ Safety Note: The replacement cost of a furnace is one thing, but the cost of losing a loved one is incomprehensible.

6a. Your Natural Gas Furnace is Producing Carbon Monoxide


Carbon monoxide is odorless, so keep an eye out for the below symptoms:

  • frequents headaches
  • irritated nose or eyes
  • nausea
  • disorientation
  • flu-like symptoms

If you notice any of these symptoms, you should open some windows, leave the house and immediately call a professional service technician or your local safety authority.

Your furnace will need to be replaced immediately in this case, so the chance to save money has passed.

❌ Repair or Replace: If you have unsafe levels of carbon monoxide in your flue gases or yellow flames and you want to continue to heat your home safely, then call a few contractors to get some quotes on a new high-efficiency furnace.

7. You Find the Air Dry or Dusty

dusty home

An old furnace, even if it’s properly maintained, usually doesn’t have the ability to adapt to effective humidifiers or air filtration and purification systems.

So, if you find yourself in a situation where you’ve bought a house that has an old furnace, and you’re finding the air in the home stale and stuffy, then a new furnace would give you the ability to add air quality accessories like the ones listed below:

  1. Steam Humidifiers
  2. Energy Recovery Ventilation Systems
  3. UV Light Air Cleaners
  4. Air Ionizers
  5. HEPA Filtration Systems
  6. Air Conditioners
  7. Heat Pumps

A lot of the products listed above can significantly improve the air quality in your home, which will not only improve how you sleep, breathe and feel but also reduce allergens, pollen, and airborne viruses.

If you would like to add any of the above accessories to your HVAC system, then it’s time to consider getting a new furnace.

πŸ”₯ Worried About the Fact That You Might Need a New Furnace?

woman thinking about furnace replacement

Making a large purchase like a new furnace is a big deal for anyone, and it can be a stressful decision to pick a furnace contractor to ensure you don’t overspend.

Here are some questions to ask your contractor when getting quotes for a new furnace:

  1. How do you calculate the capacity of the furnace for my home? Remember that new furnaces are more efficient and don’t need to be the same size as the old ones.
  2. Do I need a single-stage, two-stage, or modulating furnace and what are the pros and cons of each? Obviously, the least expensive furnace to buy is the single-stage, but it’s also the most expensive to operate. So, see if you and your chosen contractor can determine which furnace would be the best investment.
  3. There are two furnace blower motors to choose from; multi-speed and variable speed. Which is right for my home, and what are the pros and cons?
  4. Aside from the furnace brand that a contractor reps, ask if they offer other brands that might help you save a few bucks.
  5. How much can newer furnaces save you on your utility bills?
  6. Are there any government or manufacturer rebates available for new furnaces?
  7. Do you have financing available for a new furnace?

At the end of the day, a newer furnace is expensive to buy, but it will help you reduce your monthly bills and improve your home’s air quality.

One of the guidelines I recommend to customers is that if their furnace is over 12-15 years old and needs a repair that costs more than $800 to $1000, they should consider installing a new system.

πŸ”₯ Do New Furnaces Improve The Value of Your Home?


A few large repairs in a home can make a potential homeowner cringe when you get your home inspection report, and furnaces are definitely included on that list.

By installing a new heating system from a professional HVAC contractor, you’ll not only improve your home’s value, but your furnace will be installed safely and effectively.

Finally, whether you ended up needing to repair or replace your furnace, you should seriously consider hiring a professional HVAC contractor to perform annual furnace maintenance checks.

These checks will ensure many years of safe and comfortable operations without overpaying the utility company.

For more articles about furnace repair, you can easily use our search function to find what you need.

Jake Gibson

Jake Gibson is a force to be reckoned with in the HVAC industry. As the CEO of Phyxter, he has made it his mission to revolutionize how contractors work. With a background in HVAC, entrepreneurship, and technology, Jake brings innovation and expertise to this traditional industry.

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Phyxter (pronounced Fix-ter) is a national home services brand specializing in Residential HVAC, Electrical and Plumbing solutions.

Phyxter is laser-focused on writing the best articles and guides to empower homeowners to get the best out of their homes.

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