The winter chill has set in, and suddenly, your furnace is not heating your home. You’re scrambling to determine why and decide whether to call a professional.
Any HVAC expert will suggest scheduling heater maintenance at least once a year, usually in the fall. Neglecting to maintain your heating system increases the risk of being left in the cold. However, there are many reasons your furnace may stop providing heat. We’ll look at the most common ones, so you know where to look and when to call for HVAC service.
Your Thermostat Is On the Wrong Setting
An incorrectly set thermostat can prevent your furnace from working. If warm air isn’t blowing from the vents, check whether the thermostat is set to “Heat” mode. This is the only way to get heating. If it’s in “Cool” mode, someone may have accidentally switched it or forgot to change the setting, especially if the cooling season has just started.
Fortunately, resetting the thermostat mode can resolve the problem. Or, you can set it a few degrees higher than the current room temperature to trigger a heating cycle. You may also hear the fan running if it’s set to “On” even if the furnace isn’t running. Set the fan to “Auto” so the blower motor runs only during a heating cycle. Therefore, cold air won’t blow after the furnace shuts off.
An Obstruction Is Restricting Airflow
If your furnace is not heating your home and airflow seems limited, check the air filter. Change the filter if it’s coated in dust or debris. It should be replaced every one to three months and be checked regularly for clogs.
An obstruction can also occur in a vent. Low airflow can make it seem like your furnace isn’t providing heat. Make sure the vent isn’t blocked and move any objects (rugs, furniture, etc.) in the way. Also, check whether the louvers are open; if closed, open them to restore airflow. If an item has fallen into a vent and blocking airflow, remove it by hand or with a long wire if possible.
A Lack of Gas
Without gas, your furnace will turn on but not produce heat. If this is the case, check the gas valve on the supply line and open it if necessary. Furnaces that use liquid propane or oil have a tank that may need to be refilled. But if your heating system uses natural gas, check whether there are any interruptions in utility service. Call a heating contractor if there are any uncertainties about the issue.
Gas cannot combust to create heat if a furnace’s ignition system fails. Older models use a pilot light. If you have an older furnace, check whether the pilot light is lit and follow the manufacturer’s instructions for relighting it. Call for help if it doesn’t light or is yellow instead of blue.
Many furnaces have an electronic ignition system. A dirty ignitor switch can prevent a unit from running. Gently clean the metal strip on the switch if this is the case. However, ignitor switches are extremely fragile, so be careful or call a professional if it appears excessively dirty or worn.
Dirty Air Ducts
Clogged ductwork prevents heat from reaching rooms even if your furnace works fine. Dust, debris, mold, and other contaminants can clog ducts, restrict airflow, and recirculate in your home. While changing the air filter as recommended helps protect ducts, if you find debris or mold on or around registers or inside air ducts, schedule a professional air duct cleaning.
Poor insulation can be another reason for a furnace not heating your home. Whether it’s the wrong type of insulation or it has deteriorated over time, it may be causing heat to escape and cold air to seep in. If insulation absorbs moisture, this can cause problems. Older insulation may have simply exceeded its life expectancy. The latest foam insulation effectively prevents heat from escaping, filling tiny holes and cracks.
The Furnace Is the Wrong Size
The previous owner of your home may have installed the cheapest option rather than taking the time to find the right-sized furnace. Furnace capacity is measured in British Thermal Units (BTUs). Consider the average home requires 30 BTUs per square foot. Therefore, if you know the square footage of your home, you can estimate the size of the furnace you need. A higher BTU output system may be required in a colder climate.
Your Heating System Is Old
Furnaces typically last around 15 years, if they’re maintained properly. However, some can last longer. A malfunctioning heating system may have a failing blower motor or a cracked heat exchanger. Often, multiple problems crop up with age, and replacing your furnace with a newer, high-efficiency model becomes more cost-effective.
Is Your Furnace Not Heating Your Home? Call Monarch Home Services
Our team is available 24/7 to address heating emergencies in Bakersfield, Fresno, and surrounding areas. If you can’t figure out why your furnace won’t provide heat, we’ll diagnose and fix the problem quickly. Monarch Home Services is also trusted for high-quality heater maintenance services that can reduce repair costs. Sign up for a Maintenance Agreement to receive annual furnace inspections and tune-ups. To learn more or request service, call (661) 215-6657.