Whether it’s a leaky furnace or if you throw the switch to power up your heating system in the fall and it won’t start, common furnace problems can strike your home at any moment.

Regardless of the problem, learning how your heating system works and a little bit about some frequent furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional assistance. By noting the furnace's behavior, listening for peculiar noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're unsure about the problem or lack the necessary skills and tools, it's best to call a professional HVAC company like J.L. Brady Company LLC. We can accurately diagnose the issue and complete the required repairs or maintenance, so we can get your furnace ready to go ASAP.

Here's more about what causes a furnace to leak water and eight other prevalent heating problems:

1. Your Furnace Leaks Water

A furnace can leak water for many reasons. One possibility is a condensate leak, where the water released during the combustion process is not effectively draining away. This may be due to a blocked condensate drain line or a failing condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—escaping from the furnace.

It is important to deal with water leaks promptly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at J.L. Brady Company LLC is recommended to diagnose and resolve the issue properly.

2. My Furnace Is Blowing Cold Air/Not Blowing Hot Air

Some possible causes for a furnace blowing cold air or not blowing hot air could be a malfunctioning thermostat, a problem with the pilot light or ignition system, a clogged air filter, or a malfunctioning heating element. It is also possible your furnace is overheating and shutting off as a safety precaution.

If your furnace won’t blow hot air, it's best to contact a skilled HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and suggest the proper solution.

3. My Furnace Is Not Keeping Up

A frequent reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can result in heat loss and lower efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t generate enough heat to effectively warm the space. A broken thermostat or ductwork problems can also produce inconsistent heating.

To address this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, look at the thermostat to see if it’s set right and the batteries aren’t dead.

If the problem continues, consider contacting an experienced HVAC company, such as J.L. Brady Company LLC, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting your thermostat settings.

4. My Furnace Is Not Working

If your furnace is not working, there are a couple of steps you can take to troubleshoot before calling a pro. Make sure the thermostat is set right and the batteries are fresh. If the furnace still doesn't turn on, check the circuit breaker or fuse box to verify power is reaching the unit.

If there is power but your furnace won't blow hot air, the problem may lie with the ignition system or gas supply. In that case, it's better to contact an experienced HVAC technician for diagnosis and repair.

5. My Furnace Turns On and Off

If your furnace is short cycling, that means it is turning on and off multiple times at short intervals rather than running in regular cycles like it is designed to do. This can result in inefficiency, more energy use and potential damage to your heating system.

If you suspect your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be switched out on a regular basis to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and ensure it is pointing in the right direction. Second, go to your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s a good idea to call experts like the crew at J.L. Brady Company LLC. Immediate professional attention will help restore the proper functioning of your furnace and prevent more complications and high energy bills.

6. My Furnace Hums All the Time

When your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical hardware or the blower motor. Therefore, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise doesn't go away, it is best to  employ a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a constant loud noise, it's important to address the issue quickly to prevent further damage or potential safety risks.  One common reason is a broken blower motor or fan, which can generate a grinding or screeching sound. Another possible cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's best to consult with a heating and cooling specialist.

8. My Furnace Won't Start

If your furnace refuses to turn on, make sure the thermostat is set to the right temperature, is in heating mode and the batteries are good. Then, see if the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't take care of the problem, you can check the furnace's power switch or emergency shutoff switch to verify they're in the "on" position and weren’t accidentally turned off.

If those steps don’t get the job done, contact a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Much like a furnace not turning on at all, a furnace that isn’t igniting can be caused by a clogged air filter or a tripped circuit breaker. So, inspecting the air filter and looking over your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting include a faulty igniter or faulty flame sensor. Signs of these include the furnace repeatedly making an attempt to ignite without success, a lack of heat production or the furnace is making a burning or gas smell. Both of these issues can be simply fixed by HVAC specialists like the team at J.L. Brady Company LLC.