If your furnace is working and blowing warm air, but you just aren't feeling it, you may have closed or obstructed HVAC vents/registers. Check your home for any blocked or obstructed vents and registers. You may also have excessively leaky or damaged ductwork.
Your house may not be heating up due to several reasons: a malfunctioning thermostat, issues with your heating system, blocked air filters, or inadequate insulation. It's important to check these components to identify and resolve the problem. Let's dive into each of these potential issues to see which one is yours.
Dirty air filters are perhaps the most common reason that furnaces fail to provide enough heat to a home. (They're behind plenty of other problems as well.) Over time, this air filter will become clogged with dust, dirt, and other debris.
Check the air filter first
If the filter is heavily clogged with dust and debris, it cuts down on airflow, which in turn means less heated air is getting around the house. Change the filter for a clean one if it's clogged, and continue to change it every 1 to 3 months while the furnace is running.
It's most likely an incorrect thermostat setting if you find your furnace blowing warm air, not hot. The fan is set to “on” instead of “auto.” Furnaces only pump hot air until the thermostat setting is reached, so if your fan is always on, it will blow both hot air when the furnace is heating and cold when it's not.
If your furnace is blowing hot but your home is still cold, it may be a problem with your ductwork. You may have leaky or damaged ducts that are letting hot air escape and cold air in. Sometimes a damper in the system can get miss-adjusted or come loose, thereby inadvertently blocking or reducing airflow.
Clean your Air Filters, Vents, and Ducts – A clogged air filter will struggle to meet the thermostat's set temperature since the dirt and debris buildup prevents air from circulating through the vents. And as airflow into living spaces drops, so do comfort levels.
A bad thermostat can be detected when your AC or furnace is not turning on, your HVAC systems are not turning off, the thermostat not responding, your HVAC system is short-cycling, the room temperature not matching the temperature displayed on the thermostat, and the programmed setting resetting themselves.
When temperatures drop below zero or even below freezing for extended periods of time, sometimes your furnace can't keep up. If your home is not heating up to the temperature you've set, try lowering it a few degrees. The temperature of the air coming out of your vents doesn't get warmer by turning up your thermostat.
Furnace is not producing enough heat.
This may be caused by obstructed airflow or dirty or misaligned gas burners. In some cases, airflow is obstructed by a dirty furnace air filter, and if it is replaced, the problem is solved.
You can reset the ignition on your furnace simply. To do this you must cut the power to the furnace first by turning off the circuit that powers it. Once the power is off you can remove the burner door to reveal the ignitor. Turn this to “off” and leave it off for at least 5 minutes.
If your home isn't warming up as expected, a dirty air filter, blocked vents, or thermostat issues might be to blame. Check and address these issues before considering professional assistance.
If you're cold even though your thermostat indicates you shouldn't be, your furnace likely isn't the problem. In most cases, it's working just fine. It's your home that needs attention. Lack of insulation, severe air leakage, and/or unbalanced ductwork are frequently to blame.
Dirty or worn flame sensors, blower motor problems, clogs in the condensate lines, and electrical issues are some of the many problems that can leave your HVAC system failing to deliver the temperatures you've programmed in your thermostat.
One easy thing you can do to check the accuracy of your thermostat is to do a temperature check. See what your thermostat reads. Then use a portable indoor thermometer to compare the temps. Another good way to do the temperature check is to download one of the many free apps that allow you to check indoor temperatures.
Replacing a Thermostat. You'll pay between $15 and $300 for the unit in addition to labor ($65 to $100 per hour) to replace an old thermostat with a new one. However, installing a brand-new thermostat is more involved and, therefore, more expensive.
If your thermostat won't turn on the heat in your home, change out the batteries and see if that fixes the problem. If not, your faulty thermostat could be the result of the following: A tripped breaker. Loose wiring.
If your furnace is working and blowing warm air, but you just aren't feeling it, you may have closed or obstructed HVAC vents/registers. Check your home for any blocked or obstructed vents and registers. You may also have excessively leaky or damaged ductwork.
Your thermostat will not be able to reach your desired temperature if you have something blocking the vents. Check the vents around your home and make sure you do not have any items such as furniture in the way of your vent's airflow. While you're at it, make sure all of your vents are open.
Change the furnace filter on a regular basis to prevent airflow problems. Closed or obstructed vents can also cause it to feel like the furnace isn't making enough heat, because not all of its hot air makes it through the vents into your living areas. Check all vents to make sure louvers are open.
Leave the breaker(s) off for at least 10 minutes while the system is off and “rebooting.” After 10 minutes have elapsed, go back to the breaker box and flip the HVAC breaker(s) back on.
Check Furnace Thermostat Settings
Incorrect thermostat settings can be the cause behind no heat coming out of the vents, even with the furnace blower turned on. Check the thermostat to ensure the setting is in HEAT instead of COOL. It is a common mistake that happens. The fan runs continuously when it is switched on.
Ask twenty professional HVAC contractors the question, “How Much Does A New Furnace Cost?” and you'll probably get the same answer... “It depends.” On average, the cost of a new furnace can range from $2,000 - $14,2001. However, factors like furnace efficiency, type, size, and much more can impact this range.