Should I change my furnace filter in the summer?

Author: Earl Treutel Sr.  |  Last update: Friday, February 13, 2026

No matter which way you look at it, changing your furnace filter during summer benefits you in a number of ways. Don't let the clogged furnace filters affect the working of your HVAC system or defile the air quality in your home, no matter what the season.

Are you supposed to change the furnace filter in summer?

This means your system will use an unnecessary amount of energy during the summer when rates are already higher. As we mentioned above, it's important to change your furnace filter to keep your system running as efficiently as possible, but it will also make your cooling system last much longer.

Does the AC use the furnace filter?

While many people refer to air conditioning and furnace filters as if they're different, this is not the case. Your furnace and your air conditioning system use the exact same filter, so there's no need to worry about purchasing separate filters for each piece of equipment.

What happens if you don't replace your furnace filter?

Schedule replacement at least every 90 days, for better efficiency when running the furnace. Dirt and dust accumulate in your furnace if you don't regularly replace the filter, potentially resulting in premature malfunction and expensive repair jobs.

How often do I really need to change my furnace filter?

For 1- to 2-inch filters, replace them every 1 to 3 months. For 3- to 4-inch filters, replace them every 6 to 9 months. For 5- to 6-inch filters, replace them every 9 to 12 months.

How Often Should You Change Your Furnace Air Filters?

How can I tell if my furnace filter needs changing?

However, there are some signs you can look for that indicate your filter needs to be changed.
  1. Dirt and Dust Build Up On Filter. ...
  2. More Dust Than Usual In Your Home. ...
  3. The Furnace Cycles Longer Than Normal. ...
  4. Current Filter Exceeds Manufacturer's Recommendation. ...
  5. Burning Smell or Overheating.

What happens if you haven't changed the furnace filter in a year?

Air filters that are overdue for a change are a common cause of HVAC system failure. Over time, dirt builds up in the heating and AC filters, causing components such as the motor to go into overdrive, which may eventually overheat your unit.

Do I need to change my furnace filter if it doesn t look dirty?

If the air filters are clean then you don't have to spend time and money on a new filter! Well, that might not be good. Air filters being dirty shows that they are working correctly, and if they are clean, it can show that they might not be doing their job.

Is no air filter better than a dirty one?

Is no AC filter better than a dirty one? No. A dirty filter will slightly protect against some dust particles that will damage your AC system. Its better to have a dirty filter than having no filter.

What happens if you leave your furnace filter in too long?

If you leave your furnace filter in for too long, it can become clogged and make your furnace work harder to circulate air. This can lead to increased energy consumption and can potentially damage your furnace. Additionally, a dirty filter won't be as effective at improving air quality.

Is it OK to run HVAC without filter?

You might wonder about the risks of running your AC without a filter, even temporarily. The simple answer is: not for long. Ideally, your AC should never operate without a filter for more than 6-8 hours. Going beyond this can negatively affect both your system's health and your home's air quality.

Is a humidifier necessary on a furnace?

Yes, you should run your furnace humidifier in the winter, as indoor air tends to become dry due to heating systems and cold outdoor temperatures. Keeping humidity levels between 30% and 50% is ideal for comfort and health during the winter months.

What is the difference between a furnace filter and an air filter?

Air filters better capture small allergens, whereas larger particles get trapped by furnace filters. Higher efficiency often characterizes air filters, requiring a greater Minimum Efficiency Reporting Value (MERV) rating.

Will my furnace shut off if filter is dirty?

If your filter becomes clogged, it can cause your furnace to shut off as a safety feature to prevent damage to the furnace. To fix this problem, simply replace your air filter on a regular basis. If you have pets, be sure to change your air filter more frequently.

Should you run your furnace fan in the summer?

Running the fan continuously helps improve air filtration, as it continuously draws air through the filters, trapping and removing contaminants. This can lead to better indoor air quality and a reduction in respiratory irritants.

Do I need to turn off furnace before changing filter?

Changing a furnace filter is simple. First, make sure your furnace is turned OFF so it doesn't blow air when you remove the filter. Next, locate the filter housing on your furnace. This is different for each model, but you can normally find it between the air intake and the furnace.

What are the symptoms of a dirty furnace filter?

Warning Signs of a Clogged Air Filter
  • Increased Energy Consumption. When home air filters are clogged, furnaces have to work harder to meet the desired temperature of the thermostat. ...
  • Higher Electric Bills. ...
  • Uneven or Poor Heating. ...
  • Short On/Off Cycles. ...
  • Indoor Air Pollution. ...
  • Dust. ...
  • Burning Smells. ...
  • Getting Sick.

Why is AC not blowing cold air?

First, check your filters and coils for dirt and debris that may be impeding airflow. Once you've cleaned the filters and coils, run the air conditioner with just the fan so that the ice accumulation can melt off. If the AC still doesn't blow cold air, it could be that refrigerant levels are too low.

Can I run my furnace without a filter for a day?

Your furnace can, technically, run without a filter. However, we strongly recommend you don't run your furnace without a filter for any length of time. With air constantly moving through your furnace and your home, dust and debris can quickly build up, even in a matter of minutes.

What happens if I put my furnace filter in backwards?

The most common problem you will face with a backwards facing filter is simple inefficiency. If your furnace is forced to blow air through the non-porous end of a filter, it will take more energy to do so. The blower will be overworked and you will pay more money for your heating.

Can I clean my furnace air filter instead of replacing it?

Cleaning an air filter only has two additional steps from replacing one. Again, the first step is to turn off the HVAC system. Find the service panel, open the furnace, and then locate your filter and remove it from the furnace. From here, you'll want to place it dirty side up and gently vacuum the large debris.

Why is my furnace filter so dirty after 2 weeks?

If you keep experiencing this situation in your home, we recommend you start with a whole-house duct cleaning to eliminate most of the excess dust and dirt in your home's HVAC system. Then, consult with one of our expert heating and cooling technicians to find the optimal filter for your HVAC system.

Is it bad to never change air filter?

As the system is working harder to get around clogged air filters, it can cause the entire system to overwork and eventually break. If this happens, you'll need to replace the entire system, which can cost anywhere from $4,000 to $12,000.

Do you really need to change furnace filter every 3 months?

Even if your filter appears clean, those tiny particles can still accumulate and clog it up over time. Changing your filters every 3 months is the way to maintain proper airflow, efficient operation, and great indoor air quality throughout your home.

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