Whether it’s a leaky furnace or if you flip 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 issue, knowing how your heating system works and a little bit about some common furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional assistance. By observing 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 not sure about the problem or lack the necessary skills and tools, it's best to call a professional HVAC company like Clean Air HVAC. We can accurately diagnose the issue and perform the required repairs or maintenance, so we can get your furnace working again ASAP.

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

1. My Furnace Is Leaking Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water released during the combustion process is not completely 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 lead to water—as well as dangerous gases—leaking out of the furnace.

It is imperative to address water leaks quickly to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at Clean Air HVAC is recommended to diagnose and resolve the issue effectively.

2. My Furnace Blows Cold Air/Lack of Heat

Some likely causes for a furnace blowing cold air or not blowing hot air are a malfunctioning thermostat, a problem with the pilot light or ignition system, a plugged 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 a good idea to contact a trained HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and advise you on the correct solution.

3. My Furnace Struggles to Keep Up

A widespread reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can cause heat loss and reduced efficiency. Another reason your furnace is having difficulties is because it’s not big enough for your home, so it can’t generate enough heat to completely warm the space. A malfunctioning thermostat or ductwork problems can also produce insufficient heating.

To address this, first check your home’s insulation level and make sure it’s enough to protect your home. Also, check the thermostat to see if it’s set right and the batteries are working.

If the problem won’t go away, consider consulting with an experienced HVAC company, such as Clean Air HVAC, 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 Isn't Running at All

If your furnace is not working, there are some steps you can take to troubleshoot before calling a heating specialist. Ensure the thermostat is set right and the batteries are good. If the furnace still doesn't power on, check the circuit breaker or fuse box to verify power is reaching the unit.

If there is power but no heat, the problem may rest with the ignition system or gas supply. In that case, it's better to consult an experienced HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, it means it is turning on and off often at short intervals as opposed to running in regular cycles like it should. This can cause inefficiency, higher energy bills and potential damage to your unit.

If you think your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be changed on a regular basis to ensure air flow, so if your furnace air filter is dirty you should exchange it for a clean one—and make sure it is pointing in the right direction. Next, look at your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s smart to call experts like the crew at Clean Air HVAC. Quick 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

When your furnace is making a humming noise, it often is an indication of problems with the electrical elements or the blower motor. Therefore, if you detect your furnace making a humming noise, it is critical to take action.

If the noise doesn't go away, it is better that you  employ a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a persistent loud noise, it's important to deal with the issue promptly to prevent further damage or potential safety concerns.  One common cause of this is a malfunctioning blower motor or fan, which can make a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Because of the complexity of furnace systems and potential risks involved, it's safer to contact a heating and cooling specialist.

8. My Furnace Is Not Turning On

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

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

9. My Furnace Is Not Igniting

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

Other common causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace continually making an attempt to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be easily addressed by HVAC specialists like the team at Clean Air HVAC.