Signs Your Furnace Is About to Fail: What Homeowners Should Watch For

As the temperatures start to drop, your furnace becomes the main source of heating in your home, and like all appliances, it can fail during times you need it most. The key to avoiding a complete breakdown is to know the early furnace failure signs. Understanding these signs will help you catch minor issues before they become costly problems down the road. Below, TRIO Heating, Air and Plumbing has created this helpful guide on how to tell if your furnace is failing.

Early Warning Signs of Furnace Failure

Let’s start with the most common signs that your furnace needs repair. They are:

• Rising heating bills: If your bill continues to rise without any major changes to your heating system, this is a sign that your furnace isn’t running as efficiently as it should.
• Yellow or flickering flames: In gas furnaces, the flame should glow a steady blue. Anything else suggests a combustion issue that could lead to carbon monoxide poisoning.
• Cold air: If your furnace is blowing cold air, the issues could be from the heat exchanger, the thermostat, or your flame sensor.
• Short cycling: If your furnace is turning off and on before completing a full cycle, this could be due to dirty air filters or an overheating issue.

If your unit is experiencing any of the above, it’s a good idea to schedule a furnace inspection near you with TRIO Heating, Air & Plumbing.

Common Sounds That Signal Furnace Trouble

A working furnace should make a bit of noise on start-up, but it should never make sudden and loud sounds. These can indicate a mechanical, pressure, or air flow issue. Let’s dive into what noisy furnace sounds to listen for and what each one means.

• Grinding: This usually signals a serious mechanical issue, like worn-out motor bearings or a loose part bouncing around in the furnace housing.
• Buzzing: Similar to the grinding noise, any buzzing usually means a loose part or metal-on-metal contact.
• Screeching or squealing: This is due to poor air flow from the blower motor failing to push out air.
• Hissing: This could be from air escaping a clogged filter, or something more serious like a cracked heat exchanger or gas leak.
• Banging: Any loud bang signals a delay in the ignition, which could be due to a pressure issue in the gas line.

Why Some Rooms Feel Colder Than Others

Having uneven heating in the home usually means there is a lack of proper air flow and is a failing furnace symptom. When your furnace can no longer generate enough heat to warm your entire home evenly, certain rooms, especially those farthest from the unit, will feel cold. This is quite noticeable in multi-story homes, especially on the upper floors.

Temperature inconsistencies can also be caused by a failing blower motor that can't push heated air through your duct system. This could be due to a dirty air filter, but also the increased wear and tear on a motor. As the motor weakens, it struggles to distribute warm air and causes a non-working heater.

A malfunctioning thermostat can also cause furnace problems and the unit to shut off before completing a full heating cycle — preventing all that precious warm air from reaching all areas of your home.

How Poor Airflow Can Signal a Bigger Problem

If you put your hand near your vents and only feel a weak airflow, several issues can be at play. Let’s look into each below:

• Clogged or dirty air filter: If you see that your filter is dirty and replace it, but the problem persists, you're dealing with a more serious problem.
• Failing fan motor: Over time, the blower motor or motor wheel can accumulate dust or debris or even begin to degrade, making it harder to push air through your ducts.
• Restricted air flow in ducts: Once the air leaves your furnace and passes through the filter, dirty or blocked air ducts can cause it to become trapped. This causes your unit to work harder and creates temperature imbalances.

Poor air flow is not something you want to forget about. If it’s left unaddressed, it can cause other, expensive components in your furnace to fail and lead to emergency heating repair.

When Furnace Repairs Aren’t Enough

A furnace’s lifespan is between 10 and 15 years. If your older unit has faced multiple repairs, there is no point in constantly sinking money into it. Even with frequent repairs, it will never work as efficiently as it once did. It may be time to start thinking about a furnace replacement. Always consider the 50% rule — if your older unit is facing repairs that equal up to 50% of a brand new unit, it is always more cost-effective to replace it.

There are also some repairs, like a cracked heat exchanger, that warrant a full furnace replacement. The heat exchanger is responsible for converting the fuel into heat, and it also keeps carbon monoxide away from your air supply. When it cracks, it's safer to replace the entire unit.

How to Avoid a Full Furnace Breakdown This Winter

Taking a proactive and preventive approach is the best way to avoid a full furnace breakdown in the winter. There are some DIY furnace troubleshooting tips you can do yourself, like replacing the air filters every one to three months, cleaning the exterior of the unit from dust and debris, and keeping your ducts open and free of clutter.

But the best preventive strategy is scheduling routine furnace maintenance tune-ups with TRIO Heating, Air & Plumbing. Our maintenance services will catch small issues before they become costly issues and leave your unit ready for winter. The best time to do this is in the fall before the winter rush.

Get Ahead of Furnace Failure with Help from TRIO Heating, Air & Plumbing

TRIO Heating, Air and Plumbing specializes in helping homeowners prevent emergency breakdowns during peak winter and will restore safe and even heating throughout your home. Whether your system needs repairs or has reached the point where replacement makes more sense, we provide honest, expert guidance on whether to repair or replace. Call us today to schedule a consultation and stay warm this winter.