Furnace Troubleshooting: 6 Solutions to Common Furnace Problems

An efficient furnace keeps your home warm during the colder months, but what happens when it stops working? Your furnace is used the most during the winter, leading to frequent breakdowns, making furnace troubleshooting an important skill for homeowners. Catching issues early is why regular maintenance helps keep your system running smoothly. If you are unsure of your furnace’s condition, there is no need to worry! Our specialists at Classic Aire Care are available to inspect any furnace thoroughly.

Common Furnace Problems and Their Causes

Like many appliances, furnaces can experience issues with regular use. But before you feel the need to call in a pro, you can try some troubleshooting yourself.

Furnace Not Heating

Your furnace is made of multiple components. So if one component malfunctions, it can cause the whole furnace to fail. For example, a clogged filter can impede heat flow and cause power issues. Issues with the thermostat may also cause the heat not to turn on.

Other components like the pilot light or gas valve won’t ignite if they’re broken. For some systems, the fix can be as simple as making sure any panels are closed and locked in.

Furnace Blowing Cold Air

A furnace blowing cold air is enough to raise your eyebrows. An easy fix is making sure the thermostat is set at the desired setting. You can also check areas like filters to see if there is a clog. If all else fails, check if the gas supply is sufficient for the system. In some cases, the gas shut-off valve may be stuck in the “on” position. If homeowners have oil or propane systems, the fuel may be low and need a replacement.

Frequent Cycling (Turning On and Off)

Your system’s frequent cycling can be due to your airflow being obstructed. When obstructed your heat has nowhere to go, resulting in your system shutting off. Common obstructions are dirty or clogged filters. If the ventilation is in good shape, the cycling may be due to power issues. 

Power issues can be traced back to the placement of your thermostat. Check to make sure the thermostat is not receiving any false readings. Items like space heaters or ovens can give the thermostat an incorrect input. With a wrong input, the thermostat will output incorrectly.

Furnace Won’t Turn On

The main culprit of a system that won’t turn on is power inconsistencies. Check power supplies and breakers to make sure they are not shut off or need to restart. If power is not an issue, ignition components could be the problem. Inspect the pilot light as it may need to be relit or if the igniter is in working condition. These components start the heating process, so if they are not functional, neither will your furnace.

Strange Noises from the Furnace

Varying sounds can indicate furnace issues. These sounds include:

• Rattling – Loose components that need tightening like the blower belt
• Banging – A sharp sound can indicate an issue with the gas ignition
• Clicking – Issues with the igniting process, possible issue with electricity
• Buzzing – A loud buzz indicates an issue with the electricity 

To identify the problem, inspect the condition of your system’s components. In some cases, parts are too loose or tight and need to be adjusted. In other cases, components need to be replaced entirely. It is recommended to call on a servicer to have your system inspected and adjusted. This is recommended heavily in situations where an ignition or electrical issue is present. Furnaces can be dangerous, so hiring an expert is always the best idea.

Pilot Light Problems

The pilot light is a small flame that is constantly lit in your gas furnace. It can be seen as the main heat provider for the furnace itself. This small part can become dirty over time, causing inconsistent lighting. Regular cleaning with wire or a toothbrush can clear out any debris. 

A common issue is the pilot light not being lit. Simply relight it, either by yourself or by a professional. If you decide to do it yourself, please follow the instructions in your furnace manual. 

Furnace Troubleshooting Guide 

If your furnace begins to malfunction, there are steps to take to find the issue. This involves inspecting areas and components of the system itself. 

1. Check the Thermostat Settings

The first piece to check is your thermostat. A thermostat should always be set at the “heat” setting. Ensure the temperature is set at your desired setting. The entire system may not even start if your thermostat is set in a different setting. Inspect the thermostat’s batteries. A fresh set can get your unit back on track!

2. Inspect and Replace Air Filters

A malfunctioning furnace can still produce heat, but it won’t be great. Check filters, as they can clog over time. This inhibits the airflow, creating an inefficient cycle of heat. In turn, this can lead to more energy being spent while producing weaker heat. If the filters are one use, replace them with new ones. If the filters are permanent, wash them out with water and then air dry.

3. Check the Power and Reset the Furnace

Your system may not be receiving enough power to function. Check the power switch and make sure it is set to “on” in case it was flipped accidentally. If the switch is fine, check your home’s main electrical panel. Find the panel for your furnace and flip it on and off once. Doing so will act as a reset for the system. 

If all this results in a blown fuse, your system may have worse problems. In this case, call on a professional.

4. Inspect the Pilot Light and Gas Supply

The pilot light needs a consistent gas supply to stay lit. Inspect the gas line and make sure the safety valve is switched on. If the gas is being supplied, the pilot light needs to be relit. 

Before the pilot light is relit, make sure the gas line is off. Gas should be turned off for 10 to 15 minutes before relighting. If you continue to smell gas in the air, do not try to re-light. The smell indicates a possible gas leak. In this circumstance, call the fire department and gas company.

5. Look for Blockages or Obstructions

Hot air moves through your air ducts and vents. Any obstructions block airflow. Make sure that all your available vents are open completely to ensure airflow. Inspect each vent for any possible blocks. Blockages can occur from the buildup of debris, like dirt. Cleaning out the vents and ducts allows for the heat to flow properly.

6. Check the Furnace Flame

Safely inspect the opening of the furnace. Inside should be an even blue flame which indicates normal function. If the flame burns yellow or unevenly, the burners are either dirty or have some sort of debris buildup. Cleaning the burners usually resolves this. 

This issue tends to happen to older gas furnaces. Newer models use an electric-powered ignition system. This means that the flame will only be lit when necessary.

When to Call a Professional HVAC Technician

In certain circumstances, you should call a professional for help. Situations include factors like:

• Smelling gas – indicating a possible gas leak
• Electrical issues – blown fuses, inconsistent electrical supply
• Consistent problems – need for replacement or repair
• Unusual sounds – loud hissing or banging 

Gas or electrical problems put your entire household at risk. But that’s where we come in. 

An HVAC specialist from Classic Aire Care has the expertise to diagnose any furnace issue. We provide the needed solutions and repair work to get your furnace running in time before the cold months. Regular maintenance for your furnace catches these problems right away. If left unresolved, these small problems can lead to a complete system halt, leaving you in the cold. Do not test your luck through another snowstorm and call on Classic Aire Care. Our HVAC specialists provide thorough furnace inspections and efficient solutions to ensure you stay safe and comfy all winter long.