As I write this we’re dealing with record-breaking winter weather. Colder than normal and more snow than normal.

And a lot of people are complaining that their furnace can’t keep up with the cold. Is that why you’re here?

Here are afew reasons why your furnace can’t keep up. You haven’t kept up with maintenance, such as changing your filters. Or your thermostat might need replacing. Finally, your furnace could be too small for your home—especially if outdoor temps are colder than your area’s historical average.

Let’s talk about maintenance first.

What to Do If Your Furnace Isn’t Keeping up: Maintenance

Maintaining your furnace will not only add years to its life, but it will also help it to do the best job possible. If you’re not paying for a regular maintenance package with your local HVAC company, here are the steps you need to take to keep your furnace working.

Change Your Filters Regularly

Depending on your furnace and filters, you either need to regularly replace your filters or you need to regularly clean them.

For something so easy and relatively cheap to do, filters are commonly the number one issue when it comes to any sort of problem with your HVAC system. So always check them first.

While some might think that the purpose of the air filter is only to improve overall air quality, that’s only part of its job. Some may say it’s the least important part of its job.

The main purpose of a furnace filter is to protect the blower motor from damage caused by any dirt or debris that enters the system. So over time, all of that dirt and debris collects on the filter, impeding airflow. A lack of airflow will destroy your system, and most certainly stop it from warming your home.

Professional furnace maintenance
If the only maintenance you do is changing or cleaning the filters, I recommend you call a professional once in a while to do a deeper tuneup.

Regular Maintenance

Here’s a checklist of things to do:

  • Check all electrical connections. This includes inspecting your ignition and pilot lights.
  • Lubricate all moving parts.
  • Test all safety features. This includes your limit switch, thermocouple, flame sensors, and more.
  • Inspect your thermostat.
  • Inspect your chimney and vents.

There’s a lot to check, especially in terms of safety features, so many may feel more comfortable hiring a professional. For the rest of you, you can do the maintenance by yourself.

If your furnace has been neglected for any length of time, meaning it’s received no maintenance at all other than changing filters, I do recommend that you hire a professional to do a tuneup and make sure all safety features are operational.

What to Do If Your Furnace Isn’t Keeping up: Home Improvement & Tips

Since running out and buying a new furnace may not be a feasible option for many, here are a few tips to help you keep your home warm until it’s time to make that purchase.

Some of these will cost you nothing but effort and others will come at a cost.

Insulation: Keep the Warm Air in and Cold Air Out

In some cases, your furnace may be in perfect working order but working against your environment. For example, if your home isn’t well insulated, it doesn’t matter how well your furnace works because your warm air is just leaking to the outside, while cold air works its way in.

Depending on where you live and the age of your home, it may be very poorly insulated. It’s only in the last 50 years or so that homebuilders began insulating wall cavities, so if your home is older than that you likely need to upgrade your insulation.

Make sure your attic has enough insulation and check around windows and doors for gaps and leaks. Add insulation or caulking/weatherstripping where necessary.

Insulated gas furnace
The main goal of a thermally insulated furnace is to reduce the amount of heat loss.

Use Space Heaters

Space heaters are a great way to heat small spaces. Depending on the model and type, most of them can be moved from room to room fairly easily.

Take Advantage of Sunlight

In the summer, you want to cover your windows to avoid heat gain in the home. You want to do the opposite in the winter. On sunny days, make sure your windows allow sunlight through.

Move Furniture Away from All Vents

By all vents, I mean your supply registers and return air vents. If your home is heated with a radiator, move your furniture away from that as well.

You guessed it, blocking vents also blocks the flow of heat into the room. Heat that you’re paying for.

What to Do If Your Furnace Isn’t Keeping up: It’s Too Small

When your furnace was sized for your home, it was sized based on the size of your home, its orientation, the number of windows you have and the direction they face, and finally,the normal average temperatures in your area based on history.

If any of those things have changed, this will impact how efficient your furnace is.

For example, you added an addition to your house and didn’t upgrade your furnace. Or,seasonal temperatures in your area have changed significantly and the average winter temperatures are colder than they were in the past.

Finally, whoever installed your furnace may not have done proper calculations and ultimately sold you a furnace that’s too small for your home.

Whatever the case, there’s not much you can do about a furnace that’s too small unless you’re prepared to purchase a new one.


One of the most common reasons for warm air not making it into your room is a dirty filter, meaning there’s a good chance you’re looking at a quick, easy, inexpensive fix.

Keeping up with regular maintenance will go a long way in heelping your furnace keep up with cold winter weather. However, if you’re in a situation where your furnace is too small, hopefully, one of the provided tips above will add some heat.

Thanks for reading through. Why not check out our related posts below? Maybe we can answer some other questions you might have.