Waking up to a freezing draft on a cold winter morning can send shivers down your spine. That is when you realize something is wrong with the heater, which is the last thing you want to deal with during a cold season. Do not try to fix anything if you are not well-versed with the system. While you wait for the expert to arrive, a few troubleshooting tips may help.

Check Whether the Thermostat is Working

A malfunctioning thermostat can send the wrong instructions to the furnace. Asks your HVAC to help you upgrade to a programmable thermostat. A smart device offers better control of energy consumption and indoor comfort. Before purchasing a new thermostat, make sure it is compatible with the HVAC system.

It may sound obvious, but you must make sure that the thermostat is ON and set on heat. Setting it about 5 degrees above the room temperature is recommended to check the system. If it is battery powered, don’t forget to check the battery and change when necessary, generally once a year. Another maintenance checklist homeowners tend to forget is dusting off anything that might clog a thermostat. Also, check if the date and time settings on the programmable models are correct. Some systems are set to run on a timer. 

Tweak Settings on Thermostat Fan

Wrong thermostat settings send wrong signals to the heating and cooling mechanism within your house. Since the thermostat is the system that dictates when to cool or heat a room, its settings should be the first feature to troubleshoot the issue. Your loved one may have turned on the fan because it was too hot during the day. The cold draft may mean the AC is running rather than the furnace. If the fan setting is ON, simply switch it to AUTO to restore the heat without requiring a serious furnace repair. The ON setting commands the blower fan in the HVAC system and motor to operate without ceasing even if the furnace stops working. The blower thus continues to pass on air through the ducts between the heat cycles. On the other hand, the AUTO setting prompts the blower to run only when the furnace is in action. A small tweak solves the problem of having cold air circulating in the house.  What’s more, the process takes less energy than running a regular fan 24 hours a day.

Clean or Change Clogged Air Filters 

The furnace is designed with automatic safety features that shut off the burners when overeating occurs. The burners go off to protect the heat exchanger from cracking.  When the air vents start to expel cold air, it can mean the furnace is overworking and overheating. Dirty air filters are the main culprits here. As such, the safety mechanism turns off the burners while the blower continues to blow, cooling off the whole system. Clogged air filters hinder the passage of air, making the furnace run longer while struggling to warm the rooms. Avoid incurring heavy costs on the heating repair by cleaning or replacing the filters every one to three months. You can always count on the best air solution partners to figure out all underlying issues and fix them before they get worse.

Clean the Furnace Burners

After a while, furnace burners get plugged and the heat output goes down. As the furnace struggles to maintain warmth, it starts showing difficulties when starting up or running a heat cycle. Dirt and rust often develop on metallic parts of a gas furnace burner. The clog blocks the air pipe that brings fuel to the burner. You have probably experienced this issue after moving into a house that has been vacant for a long time. It is also a major problem at the start of a cold season. A buildup of dirt, grime, and rust on the burners adversely affects the performance of the furnace. So you must have a cleaning schedule at least once per year. A neglected burner is bound to give you problems when igniting. Consult a professional to help you handle this matter. 

Maintain the Flame Sensor

A gas furnace detects flames from the burning fuel through a flame sensor. The sensor is a safety control switch. It turns off the heat cycle when the burner stops producing a flame, yet gas is flowing to the furnace. One of the elements that prevent the flame sensor from performing its job is soot from the combustion.If you haven’t cleaned the flame sensor of the furnace in the last six months, it could be the reason behind the cold indoor air. Consider a professional cleaning to keep the system in the right condition. Leaving the flame sensor dirty for months will only increase the maintenance costs of the furnace. 

Adjust Thermocouple Position

So the pilot light won’t ignite. It works for a moment but, when the furnace tries to fire, it stops immediately. When the pilot light dies, it means the fuel is not burning. Unless you ignite the pilot light, the furnace will keep blowing cool air.The most probable reason behind this problem is a malfunctioning thermocouple. This is a heat-sensitive copper rod the pilot flame hits directly. Should the pilot light go off, the thermocouple is one component that controls the gas flow. If the mechanism is faulty, your house might experience a catastrophic buildup of gas. First, you need to locate the thermocouple using a screwdriver and a flashlight. Shut off the main source of power and the gas valve to maintain safety. Look for the copper rod’s tip, because that is where the thermocouple is. Be sure to use the right procedure before relighting the pilot light. First, the gas control must be in the pilot position. Hold it when igniting the pilot with a piezoelectric spark or lighter. When the flame starts, hold the button for at least 20 seconds until the thermocouple is hot enough. Once the thermocouple heats up, it instructs the gas valve to remain open and the pilot light continues to burn after releasing the control. The pilot flame must completely envelop the thermocouple’s top. If not lined up properly, it fails to detect the flame, hence shutting the gas flow. 

So, why does the thermocouple fail? This device gets broken once in a while. It can also burn out and close the gas valve. In such cases, you need to replace it if you are mechanically experienced. Otherwise, it shouldn’t cost you much to hire a professional.If the thermocouple gets dirty, it tends to affect the flame. Due to continuous exposure to a hot flame, it retains residues and wears down. Fix this by removing the device and scrubbing it with a wire brush. Do this once per year to avoid emergency repairs.

Reset the Circuit Breaker 

If the thermostat is set to heat but the furnace is not yet producing heat, perhaps the heating system circuit breaker has been tripped. At the breaker panel, find out if the fuse or circuit breaker is in the middle position or “OFF.” To manually test the breaker, flip and reset it to the ON position. If it doesn’t turn on, the circuit breaker may be defective and need replacement. Or, there could be an issue with the circuit wiring. 

Restore the Blower Door to its Position

The furnace door has a safety switch that keeps the burner and fan from functioning when you remove the access panel. If you remove the furnace door, the safety switch will pop out. Unless the door is in the right place, the furnace cannot operate. Sometimes, a replacement safety switch is necessary. If you must replace it, switch off the power and prepare the blower door. Then connect the safety switch to the circuit and test the installation.

Clear Condensate Drain Clogs

 A high-efficiency furnace produces condensed water that escapes through a drain line. A slight blockage in the drain line can make the overflow kill switch turn off the furnace to prevent water damage. Any water standing around the furnace means that the condensate line has been blocked.To clear the drain clog, turn off power at the breaker and locate the drain pan using a vacuum. Remove the water sitting in the pan. Wash the pan with soap before replacing it. Note that the condensate drain pipe extends from the pan to the outdoors or an appropriate drain. Hook up a wet/dry vacuum to the opening so it can suck out the clog.

Clean the Pilot Opening

Dirty particles may block the pilot orifice and if left unattended, the pilot light will be going out when the furnace wants to heat up. Close the gas valve before undertaking any step. To clean the pilot orifice, you have to disconnect the pilot tube from the gas control module. Note that the thermocouple and pilot tube are screwed together so you have to loosen them to take out the pilot tube. You can clear most debris in the tube by forcing compressed air in. Poke a needle in the orifice to eliminate the rust. When assembling back the pilot tube, position the thermocouple one inch from the pilot orifice.

Repair Leaking Ducts

Duct leaks can also make the furnace blow cold air. They are the passages through which heat energy escapes, and your house will not feel as warm as expected. Hot air escaping the ductwork is a waste of energy and increases your utility bills. You need to identify duct leaks and have a technician repair them.

Fix the Control Panel

There could be an issue in the control panel that causes the furnace to blow cold air. The solution for this is to reset the electronic system. At the main switch, turn off the furnace then wait for some minutes to turn it on. It is like rebooting a computer to fix an issue with the software. If the problem persists, call a technician for advanced repair.

Clean the Gas Valve

A faulty gas valve can prevent the pilot light from igniting. Make sure there is no dirt and debris on your system.Adjust the Electronic Ignition.Modern furnaces are designed with electronic ignition systems like a hot surface ignition or an intermittent pilot. Examine carefully to adjust or replace the faulty parts. Visit an HVAC company for a professional fix.

Supply Enough Gas

If the furnace is receiving an insufficient amount of gas, it might lock down since the fuel does not suffice to produce hot air. Make sure the source of gas is not turned off. If there is a severed line, do not handle it by yourself. Call a trained professional. 

HVAC Technician Solves All Your Furnace Troubles 

The job of a furnace is to distribute warmth throughout your house and keep household members comfortable when it is chilly outside. If the furnace is not generating heat, it becomes a cause of alarm. Sometimes, it is a small glitch that you can troubleshoot yourself, like adjusting a thermostat setting or checking the circuit breaker.While there are a few fixes you can handle, sometimes the problem needs professional attention. If you recently changed the air filter and the thermostat is doing fine, you will have to call an expert to take a look at it. Generally, do not try to repair or replace anything if you are not familiar with the technicalities of the HVAC unit.Other instances to call a pro to include when the finance makes rumbling noises. Also seek expert advice if there are strange smells or smoke from the furnace. Stay out of the house if there is a sulfur-like (rotten eggs) smell. This could be a gas leak and demands quick professional assistance.

As you have noted, there are numerous reasons a furnace blows cold air. If it is not a simple fix, you must always seek help from the right pros in Montgomery, Alabama. An expert provides the right help to fix the furnace so your family can continue to enjoy warmth when the weather gets cold. Keep in mind that most of the furnace issues are preventable with regularly scheduled maintenance.

Since 1991, AirNow Cooling & Heating has been servicing all HVAC equipment by all brands. No project is too big or too small for us. Whether you are in Montgomery, Millbrook, Wetumpka, or Prattville give us a call and we are ready to answer.