A functional central heating unit is essential for a comfortable home during the cold winter months. It’s important to troubleshoot any issues that arise with your central heating unit to save money on repair costs and ensure that your home stays warm and cosy.
In this article, we’ll discuss the common issues that can cause a central heating unit to malfunction and provide steps on how to troubleshoot and fix them.
Some of the most common symptoms of a dysfunctional central heating unit are as under:
- Is your heating unit blowing cold air?
- Does one room feel colder than the other?
- Is your filter causing some noise (because of some blockage)?
- Are the blowers working or even spinning the way they used to?
- Are the electrical components (thermostat, fuse, or circuit breakers) getting too hot?
If so, we might have some useful tips and advice that can help your heating system get back on track, and can warm up the room the way it used to.
#1 Check the Furnace
The furnace is a critical component of the central heating unit. When troubleshooting a central heating unit, it’s essential to check the furnace first.
Here are the steps to follow when checking the furnace:
- Confirm that the furnace is receiving power: The first step is to check that the furnace is receiving power. If it’s an electric furnace, check the circuit breaker to ensure that it’s not tripped. If it’s a gas furnace, make sure that the gas valve is open.
- Check for any signs of physical damage: After ensuring that the furnace is receiving power, the next step is to check for any signs of physical damage. Look for any cracks, rust, or damage to the exterior of the furnace. If you notice any damage, it’s essential to contact an HVAC professional to make repairs.
- Listen for any unusual noises: When the furnace is running, listen for any unusual noises such as rattling, squeaking, or banging. Unusual noises can indicate a problem with the blower motor, circulating pump, or another component of the furnace. If you hear any unusual noises, it’s essential to investigate further or contact an HVAC professional for assistance.
#2 Dirty Flame Sensor
The flame sensor is a metal rod that’s positioned near the pilot light or burner of the furnace. When the burner ignites, the flame sensor detects the presence of the flame and signals the gas valve to remain open, allowing the furnace to produce heat.
Over time, the flame sensor can become dirty, and this can cause the gas valve to close, preventing the furnace from producing heat.
Signs of a dirty flame sensor: One of the most common signs of a dirty flame sensor is a furnace that starts and stops frequently or won’t start at all.
This can be caused by the gas valve closing due to the flame sensor not detecting a flame. Additionally, the furnace may emit a burning smell or produce black soot on the furnace or vents.
How to clean a flame sensor?
To clean the flame sensor, first, turn off the furnace and allow it to cool down. Locate the flame sensor and gently remove it from its bracket.
Use fine-grit sandpaper or a soft cloth to gently clean the sensor’s metal rod. Be careful not to damage or scratch the metal rod. Once you’ve cleaned the sensor, reattach it to the bracket and turn the furnace back on.
#3 Thermostat
The thermostat is the control center of the central heating unit. It’s responsible for regulating the temperature in the home by turning the furnace on and off.
- Ensure that the thermostat is set correctly: The first step is to ensure that the thermostat is set to “heat” and the temperature is set correctly. If it’s a programmable thermostat, ensure that the schedule is set correctly.
- Check if the thermostat’s batteries are working: Many thermostats use batteries to power the device. Check the thermostat’s batteries and replace them if necessary. Low batteries can cause the thermostat to malfunction or not display the correct temperature.
- Verify if the thermostat is receiving power: Check if the thermostat is receiving power by checking the circuit breaker. If the thermostat is not receiving power, the furnace won’t turn on. If the circuit breaker is tripped, reset it and try again.
#4 Dirty Air Filter
It’s responsible for trapping dust, dirt, and other debris in the air and preventing it from circulating through the system.
Over time, the air filter can become dirty and clogged, reducing the efficiency of the central heating unit. A dirty air filter can reduce airflow, forcing the unit to work harder and consume more energy.
Additionally, a dirty air filter can cause damage to the blower motor or other components of the system.
- Signs of a dirty air filter: One of the most common signs of a dirty air filter is reduced airflow through the vents. This can cause uneven heating and make it harder for the central heating unit to maintain the desired temperature. Another sign of a dirty air filter is the accumulation of dust or debris around the air filter or vents. Additionally, a dirty air filter can cause the furnace to shut down or fail to turn on.
- How to replace or clean an air filter: To replace or clean an air filter, first, turn off the central heating unit and allow it to cool down. Locate the air filter, which is typically located near the furnace or in a return air vent. If the filter is disposable, remove it from its housing and dispose of it. If it’s a washable filter, follow the manufacturer’s instructions to clean it. Be sure to let the filter dry completely before reinstalling it.
It’s recommended to replace or clean the air filter every 1-3 months, depending on how frequently the central heating unit is used and the air quality in the home.
#5 Bad Inducer Motor
The inducer motor is a small electric motor that helps a gas furnace expel combustion gases through the furnace and out of the chimney or vent.
It’s a critical component of the furnace and helps ensure that the furnace operates safely and efficiently. Over time, the inducer motor can become worn out or damaged, preventing it from functioning correctly and causing a range of issues with the furnace.
- Signs of a bad inducer motor: One of the most common signs of a bad inducer motor is a furnace that won’t start or won’t stay running. You may also hear a loud humming or buzzing noise coming from the furnace. Additionally, the furnace may emit a burning smell or produce black soot around the furnace or vents.
- How to replace an inducer motor: To replace an inducer motor, first, turn off the furnace and allow it to cool down. Locate the inducer motor and disconnect it from the furnace. Install the new inducer motor, making sure to connect all wires and screws securely. Once the new inducer motor is installed, turn the furnace back on and test it to ensure that it’s working correctly.
Replacing an inducer motor can be complicated and should only be performed by a qualified HVAC professional. Attempting to replace the inducer motor yourself can cause further damage to the furnace or result in personal injury.
#6 Bad Blower Motor
The blower motor is an electric motor that’s mounted inside the furnace or air handler. It’s responsible for circulating warm air through the ducts and into the rooms of your home.
- Signs of a bad blower motor: One of the most common signs of a bad blower motor is reduced airflow through the vents. This can cause uneven heating and make it harder for the central heating unit to maintain the desired temperature. Another sign of a bad blower motor is a loud humming or buzzing noise coming from the furnace. Additionally, the blower motor may fail to turn on or turn off too frequently.
- How to replace a blower motor: To replace a blower motor, first, turn off the furnace and allow it to cool down. Locate the blower motor and disconnect it from the furnace. Install the new blower motor, making sure to connect all wires and screws securely. Once the new blower motor is installed, turn the furnace back on and test it to ensure that it’s working correctly.
#7 Igniter or Pilot Light
The igniter or pilot light is a small flame that’s used to ignite the gas in the combustion chamber.
Some furnaces use a standing pilot light, which is always lit, while others use an electronic igniter, which only lights the gas when the furnace is turned on.
- Signs of a faulty igniter or pilot light: One of the most common signs of a faulty igniter or pilot light is a furnace that won’t start or won’t stay running. You may also hear a clicking or sparking noise coming from the furnace. Additionally, a faulty igniter or pilot light can cause the furnace to produce a burning smell or not heat the air correctly.
- How to replace an igniter or pilot light: To replace an igniter or pilot light, first, turn off the furnace and allow it to cool down. Locate the igniter or pilot light and disconnect it from the furnace. Install the new igniter or pilot light, making sure to connect all wires and screws securely.
Once the new igniter or pilot light is installed, turn the furnace back on and test it to ensure that it’s working correctly.
#8 Leaky Air Ducts
Air ducts play a critical role in maintaining the air quality and comfort of your home.
They’re responsible for distributing warm air from the central heating unit to the rooms of your home, ensuring that you stay warm and comfortable during the colder months.
Over time, the air ducts can become worn out or damaged, leading to leaks and reducing the efficiency of the central heating unit. Here are the steps to follow when troubleshooting leaky air ducts:
- Signs of leaky air ducts: One of the most common signs of leaky air ducts is uneven heating throughout your home. You may also notice that some rooms are colder than others or that the airflow through the vents is weak. Additionally, you may hear whistling or rattling noises coming from the air ducts.
- How to repair leaky air ducts: To repair leaky air ducts, first, locate the area where the ducts are leaking. This may require crawling through the attic or crawlspace to inspect the ducts. Once you’ve located the leak, use duct sealant or foil tape to seal the leak. Be sure to use a high-quality sealant or tape that’s designed for use with air ducts.
#9 Lack Of Fuel
The most common reason for a lack of fuel is that the tank is empty or nearly empty.
Other reasons may include a clogged fuel line, a faulty fuel pump, or a malfunctioning fuel gauge.
- How to check for fuel levels: To check the fuel levels, locate the fuel tank and inspect the gauge. If the gauge shows that the tank is nearly empty, it’s time to refill the tank.
- How to refill fuel levels: Refilling the fuel tank is a simple process, but it’s important to follow the proper safety precautions. First, turn off the furnace and allow it to cool down. Locate the fuel tank and unscrew the cap.
Fill the tank with the appropriate fuel, taking care not to overfill. Once the tank is full, replace the cap and turn the furnace back on.
#10 Press Your Heater’s Reset Button
Some modern central heating units have a reset button. Find out if yours has one.
The reset button is typically located on the furnace or boiler and is designed to shut off the unit if it detects a problem.
Here are the steps to follow when resetting your heater’s button:
- Locate the reset button: The reset button is usually a small red or yellow button located on the furnace or boiler. It may be labeled as “reset” or “restart.”
- Turn off the furnace or boiler: Before pressing the reset button, it’s important to turn off the furnace or boiler and allow it to cool down. This will help prevent damage to the unit and ensure your safety.
- Press the reset button: Once the furnace or boiler is cool, locate the reset button and press it firmly. You may need to hold the button down for a few seconds.
- Turn on the furnace or boiler: After pressing the reset button, turn on the furnace or boiler and allow it to run for a few minutes. If the unit starts and operates correctly, the problem may have been a temporary issue that was resolved by resetting the button.
Types Of Central Heating Systems
| Type of Central Heating Unit | Description | Commonly Used in | Difficulty Level of Repair/Troubleshooting |
|---|---|---|---|
| Furnace | Heats air using natural gas, propane, or oil and distributes it through ducts | North America | Moderate |
| Boiler | Heats water or steam and circulates it through pipes to radiators or underfloor heating systems | Europe and other parts of the world | Difficult |
| Heat pump | Transfers heat from the air or ground outside your home to heat or cool the air inside | Worldwide | Moderate to difficult |
| Electric heating | Uses electricity to heat air, water, or radiant flooring systems | Areas where natural gas or propane is not available | Easy |
| Solar heating | Uses the sun's energy to heat water, which is then circulated through pipes to heat your home | Areas with ample sunlight | Moderate |
| Geothermal heating | Uses the earth's natural heat to warm your home | Worldwide, but most common in areas with high heating loads | Difficult |
Do You Need A HVAC Technician?
If your system still lags despite following all of the steps mentioned above, it likely needs servicing.
Before making any changes, troubleshooting the system, or deploying a new central heating unit, you must understand how your system is built altogether.
It would be worthwhile to explore and invest some time with an expert to examine the pros and cons of each of the systems, and how you can fix and maintain the most common issues when they arise.
We hope that this helps you make a better and more informed choice when you’re making one.
