Can I Replace Furnace Without Replacing AC?

San Rafael

(415) 942-6565

Santa Rosa

(707) 452-3464

Every HVAC system reaches the end of its average lifespan at some point. Whether it is crazy sounds, short cycling, odd smells, or just a failure to create heat, these are all signs that it might be time to replace your furnace. But what does that mean for your air conditioner? If the furnace and air conditioner are connected, does that mean you have to replace both systems, even if only one is inoperable?

The design of every HVAC system can be complex with all its different equipment and connections. Therefore, the thought of somehow replacing the furnace without replacing the air conditioner can be intimidating. There is the efficiency of the system to consider, as well as cost and balancing what will work in the long run. We have seen natural gas and propane prices rise steadily over the last decade.

That is why today’s article is going to walk you through every possible solution and factor to consider, from the decision to try to repair your furnace instead of replace it. After going through the repair process, sometimes factors like cost to repair make it so that it is indeed best to replace both systems or just one.

Repair Or Replace Air Conditioners: Things To Check First

A lot of times, repairs may be a better option than going for a full-blown replacement for your faulty furnace. Because a furnace has many moving parts, it is likely that repairing just one component, like replacing an evaporator coil, can be the solution to restoring your unit to working order. These repairs can be done by a professional HVAC technician or even by yourself! Here are some possible problems that might be causing your furnace to malfunction:

1) The Air Filters: Dirty air filters are a common problem that can cause issues with a furnace system. A filter can become clogged with the amount of debris that blocks circulation and creates pressure on the fan motor, which has to work incredibly hard to try to move air past it. This can lead to the motor burning out, not to mention increased utility bills. Changing the filters every two to three months is a good way to prevent this from happening.

2) The Thermostat: If the furnace’s connection with the thermostat is encountering troubles, this is a very good reason why the system is not performing as it should. It is possible that the thermostat might be the issue rather than the furnace itself, especially if you need to replace the batteries.

3) The Circuit Breaker: Sometimes the furnace might not even be on. Circuits can be switched off for a number of reasons. Check to make sure that the circuit breaker for the furnace is on (switch facing the same direction as the rest), and if it is, switch it off and then back on again to see if that helps to reset the system and get it running again.

4) The Pilot Light: If you have an older furnace, you probably have a pilot light. In older furnaces, this is the small flame that lights the furnace so that it can begin heating. It is possible this light has gone out, therefore causing the problems with the furnace. You can relight it yourself if you know how to safely do so, or hire a contractor to relight it safely with the proper HVAC equipment.

When It’s Time To Replace Your Furnace

So you’ve gone through the possible repairs to be made, but the furnace is still having problems. Though things like maintenance and repair can significantly extend a system’s lifespan and save money for you in the long run, there are cases where replacement is the better, and sometimes only, option.

If your furnace is more than 15 years old, then it is a good idea to think about replacement. The life expectancy of a furnace is between 15 and 30 years. As a furnace gets closer to the 30-year mark, it will be much less efficient.

If utility bills are consistently getting higher, this is also a sign that the furnace might need replacing. The older a furnace gets, the harder it has to work to heat your home, resulting in more energy being used.

Another sign that it is time to replace your furnace is when it begins to make an incredibly loud noise when it runs. Intense rattling or screeching? This is not the usual noise for a furnace to be making, and indicates that something is most likely very wrong with the unit.

Furnace Or Air Conditioning System: Can You Replace Just One?

If you have decided that replacement is definitely the right choice for your furnace, now you have to determine how you want to go about the process with a connected furnace and air conditioner. Are you able to replace them separately?

When it comes to connected heating and cooling systems, they work in such a way that the cooling systems don’t interfere with the heating systems since the AC is connected to the furnace, not the other way around. Therefore, if you were to just replace the AC separately from the furnace, it would most likely do no harm since the AC has its own set of components, like condensers and evaporator coils, that do not intersect with the furnace components.

However, since the AC unit is attached to the furnace system, that means it does rely on the furnace to operate as it does. However, there are some scenarios where you do not have to replace your furnace and air conditioner at the same time if you are only looking to replace your furnace.

One case is when prospective new furnaces are compatible with your existing air conditioners. In fact, there are times when a new furnace may actually boost the performance of your air conditioning system, since the furnace is what determines how well the AC operates. If you want to go without replacing both systems at the same time because your air conditioning is working fine, it might be possible to find a new furnace that will work just as well or even better with the air conditioner you have now.

It is usually not recommended to replace air conditioners less than 10 years old anyway, so if your air conditioner is relatively new and still operating how you would like it to, there is no need to replace both systems if you only need to replace one.

Replacing the Furnace and Air Conditioner

Of course, there are many cases in which replacing both the furnace and air conditioner may be the best option. There are many benefits for homeowners from replacing both at the same time, which is why it is often recommended. While it is true that the furnace can survive just fine without the AC because of their many separate working parts, they also have many components that go together (for example, the blower motor that sends the conditioned air into your house). Here are the biggest reasons why replacing furnaces and air conditioners together makes sense:

Better Overall Efficiency

Though it might be possible to find a furnace that is compatible with your air conditioner, it is nice to be extra sure that everything is synced up perfectly. To make sure each unit works with as much efficiency as possible to bring comfort to your home, it is best that they are installed together. You can ensure they are both the right size and that all of their inner workings can run as they should.

More Cost-friendly

One great reason for homeowners to replace both systems at once rather than one at a time, is the money that will be saved on the cost of having another unit installed in the future. While it may seem pricey to have your entire HVAC system replaced at once, it will save you money and labor in the long run because you will not have to worry about another replacement for any part for a very long time with two brand new units. Replacing one unit without replacing the other might result in continuous future costs down the road if you constantly have to make adjustments so that both systems work correctly together. And if your AC is old enough, it might soon begin to have problems itself, resulting in another new installation and adjustment period.

Upgrade for Both Units

When you are replacing your furnace, it is a great time to upgrade both it and your air conditioner to newer models that can give you improved comfort with more recent technology. When only replacing your furnace, you might have a very efficient brand new furnace, while the AC unit remains outdated. Replacing both with newer models can help make sure every part of your new entire system is improved for maximum efficiency and that all parts operate together to bring the perfect flow of air into your home.

When it comes to replacing any heating and cooling unit, there is no universal answer, and there are always many factors to consider. Ultimately, the choice will come down to what your heating and cooling system goals for your home are, and what will align best with them. Replacing furnaces without replacing air conditioners is possible, but it is not the most efficient choice.

Remember that a professional HVAC contractor, like John Owens Services, can help you through the process of deciding what the best route to take is with your HVAC system. We will make sure you have all of the right equipment before and during the installation job, and we will make sure you have all of the information available about your system options. Professional technicians can perform tasks such as load calculation to determine the proper size for furnaces and ACs and can double check that things like the evaporator coils are functioning.

You can always check for possible repairs to be made if your furnace seems to be malfunctioning, and if it does need to be replaced, you do not necessarily have to replace your air conditioner along with your furnace if you find a furnace replacement that will sync well with your current air conditioning, and it is not recommended to replace your air conditioning if it is less than 10 years old.

But replacing both the furnace and air conditioning system can save you a lot of money on HVAC installation costs in the long run, as well as ensure that you are up to date on the most current system technology for both systems that can bring comfort to your home during extreme weather seasons. Having your heating and cooling work cohesively is vital for your comfort!

If You Need A Professional

John Owens Services has been installing HVAC units in homes since 1986. Our service area includes all of Sonoma County and Marin County. Call today if your heating and cooling system needs to be inspected for the health of the units. If you are looking to electrify, we are also experts in heat pump heating and cooling systems. From air-to-water to air-to-air, ducted to ductless, we can install them all. We can give you free estimates to repair or even replace your furnace and air conditioner.

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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464



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San Rafael
(415) 942-6565
Santa Rosa
(707) 452-3464