Whether it’s a leaky furnace or if you throw the switch to turn on your heating system when the weather gets cold 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 services. By observing the furnace's behavior, listening for strange 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 reputable HVAC company like Interstate Heating & Air Conditioning. We can accurately pinpoint the issue and execute 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 properly 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 imperative to address water leaks promptly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at Interstate Heating & Air Conditioning is recommended to diagnose and resolve the issue successfully.

2. My Furnace Blows Cold Air/Lack of Heat

Some likely 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 mechanism.

If your furnace won’t blow hot air, it's best to contact a trained HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend 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 reduced efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t make enough heat to effectively warm the space. A broken thermostat or ductwork problems can also produce uneven heating.

To deal with this, first check your home’s insulation level and make sure it’s enough to insulate 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 Interstate Heating & Air Conditioning, 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 Won't Work

If your furnace is not working, there are a couple of steps you can take to troubleshoot before calling a heating specialist. Ensure 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 rest with the ignition system or gas supply. In that case, it's a good idea to contact an experienced HVAC technician for diagnosis and repair.

5. My Furnace Short Cycles

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

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged 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 be sure it is pointing in the right direction. Second, look at your thermostat and make sure  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 Interstate Heating & Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and prevent further complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is a sign of problems with the electrical parts or the blower motor. Therefore, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is a good idea to  contact a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is emitting a constant loud noise, it's important to handle the issue promptly to prevent further damage or potential safety concerns.  One common problem that causes this is a broken blower motor or fan, which can make a grinding or screeching sound. Another potential 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 better 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 functioning properly. If these basic checks don't address 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 get the job done, contact a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Like a a furnace that will not on at all, a furnace that isn’t igniting can be caused by a dirty 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 are a faulty igniter or malfunctioning flame sensor. Symptoms of these include the furnace continuously making an attempt 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 solved by HVAC specialists like the team at Interstate Heating & Air Conditioning.