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

Regardless of the issue, knowing how your heating system works and a little bit about some common furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional services. By observing the furnace's behavior, listening for unusual noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're uncertain about the problem or don't have the necessary skills and tools, it's best to call an experienced HVAC company like Comfort Concepts Heating & Air Conditioning. We can accurately identify the issue and complete the required repairs or maintenance, so we can get your furnace up and running ASAP.

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

1. My Furnace Is Leaking 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 properly draining away. This could be due to a plugged condensate drain line or a malfunctioning condensate pump. Another likely 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 imperative to correct water leaks immediately to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Comfort Concepts Heating & Air Conditioning is recommended to diagnose and resolve the issue properly.

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

Some likely causes for a furnace blowing cold air or not blowing hot air include a malfunctioning thermostat, a problem with the pilot light or ignition system, a clogged air filter, or a malfunctioning heating element. It also may be 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 trained HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and recommend the correct 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 doesn’t have enough insulation, which can cause heat loss and lower efficiency. Another reason your furnace is having difficulties is because it’s too small for your home, so it can’t generate enough heat to effectively warm the space. A defective thermostat or ductwork problems can also cause insufficient 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 make sure it’s set right and the batteries aren’t dead.

If the problem continues, consider contacting an experienced HVAC company, such as Comfort Concepts Heating & Air Conditioning, who can look over your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying 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 contacting a pro. Make sure the thermostat is set right and the batteries are good. If the furnace still doesn't start, check the circuit breaker or fuse box to ensure power is reaching the furnace.

If there is power but your furnace won't ignite, the problem may rest with the ignition system or gas supply. In that case, it's a good idea to reach out to an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, this means it is turning on and off often at short intervals rather than running in regular cycles like it ought to. This can cause inefficiency, more energy use and potential damage to your unit.

If you believe your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be changed when they are dirty to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and be sure it is pointing in the right direction. Second, look at your thermostat and look to see if  it’s set right and the batteries are good.

If those two things don’t work, it’s best to call experts like the crew at Comfort Concepts Heating & Air Conditioning. Immediate professional attention will help restore the proper functioning of your furnace and prevent more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

If your furnace is making a humming noise, it often is a symptom of an issue with the electrical hardware or the blower motor. Therefore, if you detect your furnace making a humming noise, it is crucial to take action.

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

7. My Furnace Is Making a Loud Noise

If your furnace is producing a consistent loud noise, it's important to address the issue quickly to prevent further damage or potential safety concerns.  One common reason is a malfunctioning blower motor or fan, which can generate a grinding or screeching sound. Another potential 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 get in touch with a heating and cooling specialist.

8. My Furnace Is Not Turning On

If your furnace refuses to turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are good. Then, check if the circuit breaker or fuse that controls the furnace is sending power to the unit. If these basic checks don't fix the problem, you can inspect the furnace's power switch or emergency shutoff switch to ensure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t do the job, phone a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Like a a furnace not turning on at all, a furnace that isn’t igniting can be the result of a dirty air filter or a tripped circuit breaker. So, examining the air filter and looking over your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting include a faulty igniter or faulty flame sensor. Symptoms of these include the furnace continually trying to ignite without success, an absence of heat production or the furnace is making a burning or gas smell. Both of these issues can be simply fixed by HVAC professionals like the team at Comfort Concepts Heating & Air Conditioning.