For many households, a furnace is the heart of a comfortable home during cold weather months. We rely on our furnaces to keep us warm and cozy and prevent issues like burst pipes and ice dams which can cause costly damages. Looking for signs your furnace is going out can help you avoid these situations when you know it’s time to repair your furnace. 

Unfortunately, furnaces don’t last forever and can develop problems over time. A broken furnace could lead to inconvenience, safety hazards, and significantly higher energy bills. Since problems often arise gradually, it is essential to watch for warning signs that may indicate the need for repairs instead of buying a new furnace.

Knowing the warning signs your furnace is going out can help you determine when to repair your furnace and when to replace it as well. Prompt and professional furnace repair can prevent further damage and help maintain the efficiency of your system and ensure your warmth all winter long!

To ensure the proper functioning of your furnace, watch out for these seven warning signs that it’s time to call a professional for furnace repairs:

1. Uneven Heating in Different Rooms

Uneven heating can signal that your furnace cannot function effectively. This could mean your thermostat does not match the produced temperatures or your furnace cannot generate heat correctly. Other common causes of uneven heating include blocked vents and ducts, leaking ductwork that allows treated air to escape, or a unit that’s the wrong size for your home.

When this problem arises, it means the thermostat is not correctly communicating with the unit, which is the primary function of a furnace. For example, when you set the temperature to 30°C, and the two closest rooms to the furnace register temperatures of 22°C and 32°C, it could be a sign that your thermostat needs to be recalibrated or replaced. In any case, you’re advised to bring in an HVAC professional to investigate the issue.

2. Loud Noises when the Furnace is Running

Unusual noises coming from your furnace when it’s running could be a sign of an underlying issue. These noises run the gamut from thumping, squealing, and rattling to clanking or banging when the fan is running. Noise can indicate something as minor as a loose belt or cover panel, but it could also signify parts of the unit are close to breaking.

No furnace is silent, but persistent and loud noises indicate that the unit needs to be serviced. Thumping and squealing are often signs of a failing motor or an obstructed fan blade while clanging noise can indicate a failing blower wheel or assembly. A dirty combustion chamber is the most common cause of banging noises while whistling noises can point to a belt or fan issues.

3. Bad Odours

There are several potential causes of bad odours emanating from your furnace. Some common causes include:

• accumulation of dust and dirt in the blower assembly
• overheating of electrical components. (burned or melted electrical insulation)
• improperly sealed combustion chamber or gas lines
• gas leaks or carbon monoxide
• dust, mould, and mildew can build up over time in the interior parts of the unit
• a dirty air filter or a malfunctioning heat exchanger will cause the air circulating through your home to smell musty

Sometimes, bad odours can be caused by a gas leak in the combustion chamber. Natural gas is colourless and odourless, so gas companies add a harmless chemical called mercaptan to give the gas its distinctive rotten-egg smell. If you smell this smell from your furnace, shut off the gas supply and call an HVAC technician immediately.

4. Discolored Pilot Light or Flame

The colour of the flame or pilot light should be blue, though some shades may vary. If the flame is yellow, orange, or flickers, it could indicate that the furnace is not burning cleanly and efficiently. This can be due to a gas leak, carbon monoxide buildup, or an accumulation of dirt and dust in the pilot light.

Discoloured pilots can also be caused by a malfunctioning thermocouple, a safety device that shuts off the main gas valve if the pilot flame goes out. It is important to get this checked out immediately if you notice a discoloured flame, as it could risk your safety.

5. Poor Air Quality

Apart from heating your home, a furnace also provides air circulation and cleans the air of pollutants. The furnace’s efficiency in providing clean air depends largely on the quality of its filters. A poorly maintained unit moves dirt, bacteria, and other contaminants through the air, leading to poor indoor air quality.

When you notice floating dust, frequent coughs, and other respiratory problems, it could indicate that your furnace needs to be serviced. You should also check the filters regularly and replace them with high-quality ones if necessary.

6. High Heating Bills

When the weather outside drastically changes, you can expect to see a slight increase in your heating bills. However, if your heating settings stay fairly consistent and you’re seeing an unusually high bill, your furnace may be the culprit.

The cost of running a furnace increases when it has trouble generating heat or works harder than necessary. It could be due to several issues we’ve already discussed, and a technician can identify the cause and offer solutions.

7. Frequent Cycling

Frequent cycling is the term used to describe when your furnace turns on and off repeatedly, even when no changes in temperature have been made. This is usually caused by an issue with the thermostat or a dirty heat sensor that needs cleaning, but it could also be due to a faulty motor or inefficient system running.

Usually, the lifespan of a furnace is 12 to 20 years. If your unit approaches this age, frequent cycling could indicate it’s time for a replacement or at least a thorough inspection.

These are the seven warning signs that it’s time to repair your furnace. It is important to take note of any changes in your furnace’s performance and address them immediately, as this will help maintain a safe and comfortable indoor environment. If you notice any of these signs, it may be time to call a furnace repair specialist, who can diagnose and fix the issue quickly. Your health and safety are worth the investment!