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

Regardless of the cause, learning how your heating system works and a little bit about some frequent furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional services. 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 aren't equipped with the necessary skills and tools, it's best to call a reputable HVAC company like Air Masters Heating & Cooling. 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 problems:

1. Your Furnace Leaks 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 may be due to a plugged condensate drain line or a failing 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—coming out of the furnace.

It is imperative to deal with water leaks quickly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at Air Masters Heating & Cooling is recommended to diagnose and resolve the issue successfully.

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

Some potential 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 could also be your furnace is overheating and shutting off as a safety precaution.

If your furnace will not blow hot air, it's best to contact a trained HVAC specialist to diagnose and fix the problem. They can offer an accurate assessment and recommend the correct solution.

3. My Furnace Struggles to Keep Up

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

To handle this, first assess your home’s insulation level and make sure it’s enough to protect your home. Also, examine the thermostat to see if it’s set right and the batteries still function.

If the problem lingers, consider consulting with an experienced HVAC company, such as Air Masters Heating & Cooling, 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 some steps you can take to troubleshoot before contacting a pro. Ensure the thermostat is set properly and the batteries are not dead. 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 be with the ignition system or gas supply. In that case, it's best to consult a seasoned HVAC technician for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, this means it is turning on and off frequently at short intervals instead of running in regular cycles like it ought to. This can lead to inefficiency, higher energy bills and potential damage to your heating system.

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be changed when they are dirty to ensure air flow, so if your furnace air filter is plugged with dirt you should exchange it for a clean one—and make sure it is pointing in the right direction. If that doesn’t do the trick, 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 team at Air Masters Heating & Cooling. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is an indication of a malfunction with the electrical components or the blower motor. Because of this, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise continues, it is best to  contact a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is making a persistent loud noise, it's important to address the issue right away to prevent further damage or potential safety concerns.  One common problem that causes this is a malfunctioning blower motor or fan, which can create a grinding or screeching sound. Another common cause is a loose or worn-out belt that may produce a squealing or rattling noise.

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

8. My Furnace Can't Turn On

If your furnace won't turn on, make sure the thermostat is set to the right temperature, is in heating mode and the batteries are good. Then, verify that the circuit breaker or fuse that goes to the furnace is working right. If these basic checks don't fix the problem, you can check 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 on but Not Igniting

Similar to a furnace that won't turn on at all, a furnace that isn’t igniting can be the result of a plugged air filter or a tripped circuit breaker. So, checking the air filter and taking a peek at your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Symptoms of these include the furnace continuously trying 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 easily repaired by HVAC specialists like the team at Air Masters Heating & Cooling.