When your furnace is running but blowing cold or unheated air, the issue is usually caused by a dirty air filter, a tripped safety switch, or a failed ignition component.
An improperly set thermostat can stop the heating cycle from starting, while a clogged filter may cause overheating that shuts down the burners. Ignition-related problems, such as a faulty ignitor or contaminated flame sensor, can also prevent the burners from producing heat even though the blower continues running.
Reset the Furnace
Turn the thermostat to "OFF." Locate the power switch on the furnace (often looks like a light switch) or the circuit breaker. Turn it off for 30 seconds, then flip it back on. Turn the thermostat back to "HEAT."
If your furnace is blowing air but it isn't hot, the issue usually stems from a thermostat error, a clogged air filter, or a failed ignition. To get your system back up and running, you can follow these simple steps in order.
Airflow Problems That Prevent Warm Air From Reaching Rooms
Restricted airflow is one of the most common reasons a furnace works hard, but rooms still feel cold. When air can't move freely through the system, the heat produced in the furnace never reaches your living space.
5 Warning Signs It's Time for Furnace Replacement
A frozen pipes furnace failure can cause major problems inside your home. Ice builds up fast in unheated spaces, and when frozen water expands, it can burst pipes wide open. That kind of mess is the last thing anyone wants during a winter heating outage.
7 Ways to Tell Your Thermostat Is Broken
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
To reset your furnace thermostat, first turn the system OFF. Then, perform a quick power cycle at the circuit breaker or a factory reset on the device itself, depending on your model.
All furnaces are equipped with a reset button. They are generally red or yellow and are located inside the blower compartment. The reset button is a safety feature that will shut down the furnace when a problem is detected, often a hot or overheating furnace, before it trips the circuit breaker.
If your furnace is blowing cold air, the most common causes are a dirty air filter, incorrect thermostat settings (fan set to "ON"), or a pilot light that has gone out.
The $5,000 rule is a guideline to help homeowners decide whether to repair or replace their HVAC system. You multiply the age of your unit by the cost of the needed repair. If that number exceeds $5,000, replacing your HVAC system is often more cost-effective.
Yes, you should turn the furnace off if it is continuously blowing cold air. Turning it off prevents the system from blowing unheated air, stops it from wasting electricity, and prevents further damage to the unit if there is a malfunction.
The Furnace Won't Ignite: This is the most common and most telling sign. If the gas valve doesn't open, the ignition sequence simply can't begin. Intermittent Heating or Sudden Shutdowns: These unpredictable cycles often point to weak solenoid coils or unstable electrical connections.
To get your furnace to kick on, first verify your thermostat is set to "Heat" and raised at least 5 degrees above room temperature. Next, check that the furnace power switch (usually resembling a standard light switch on or near the unit) is toggled "ON".
What fails first on a furnace? The most common early failures are the furnace ignitor or flame sensor, as they experience regular wear and tear and are critical to starting the heating cycle.
A standard residential furnace lasts 15 to 20 years. However, the exact lifespan varies based on the type of system and how well it is maintained.
Homeowners insurance may cover the cost to repair or replace your furnace or boiler if it's damaged or destroyed by a covered peril. Covered perils as defined by your policy typically include events such as: Lightning. Fire.
A stuck thermostat means the valve regulating coolant flow to your engine has failed. Symptoms depend on whether the thermostat is stuck closed (trapping heat) or open (allowing too much coolant to circulate).
Disconnect the old thermostat and unscrew the mounting plate. Check the new thermostat instructions for compatibility and wiring guidance. Connect the labeled wires to the new thermostat. Attach the new mounting plate to the wall.
Average Lifespan of a Thermostat
With a straightforward design and basic scheduling features, they are reliable workhorses that can last 10 to 15 years with proper care. Routine programming updates and occasional recalibrations go a long way toward keeping them accurate and extending their usefulness.
It's such a simple thing, leaving a single faucet dripping, but it can prevent so many complications later on. How much value does one dripping faucet have? A lot, if it keeps your home's water pipes from bursting during frigid weather.
As temps drop, the risk of having frozen pipes in your home increases. Typical high-risk areas for freezing include pipes within exterior walls, as well as exposed pipes that run through unheated or uninsulated areas such as attics or basements.
Focus on Safety and Immediate Comfort
Your first priority should always be the safety of you and your family. If the temperature inside your home starts to fall, gather everyone into one or two rooms to retain warmth. Make sure to close doors to unused spaces, add extra blankets, and dress in warm layers.