Whether it’s a leaky furnace or if you flip the switch to start your heating system when it gets chilly and it won’t start, common furnace problems can strike your home at any moment.

Regardless of the cause, understanding how your heating system works and a little bit about some typical furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional assistance. By noting 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 lack the necessary skills and tools, it's best to call a professional HVAC company like Watts Electric & AC. We can accurately identify the issue and perform 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 common heating issues:

1. Your Furnace Leaks Water

A furnace can leak water for a number of reasons. One possibility is a condensate leak, where the water released during the combustion process is not properly draining away. This might be due to a clogged condensate drain line or a malfunctioning 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 correct water leaks immediately to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Watts Electric & AC is recommended to diagnose and resolve the issue successfully.

2. My Furnace Blows Cold Air/Lack of Heat

Some potential 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 plugged air filter, or a malfunctioning heating element. It also may be 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 skilled HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend the proper solution.

3. My Furnace Can't Keep 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 make enough heat to effectively warm the space. A malfunctioning thermostat or ductwork problems can also cause inconsistent heating.

To address this, first look at 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 still function.

If the problem won’t go away, consider consulting with an experienced HVAC company, such as Watts Electric & AC, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or changing your thermostat settings.

4. My Furnace Isn't Running at All

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

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 consult a knowledgeable 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 multiple times at short intervals as opposed to running in regular cycles like it ought to. This can cause inefficiency, higher energy bills and potential damage to your furnace.

If you suspect your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be exchanged on a regular basis to ensure air flow, so if your furnace air filter is plugged with dirt you should exchange it for a clean one—and ensure it is pointing in the right direction. Second, look at 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 Watts Electric & AC. Immediate professional attention will help restore the proper functioning of your furnace and prevent further complications and high energy bills.

6. My Furnace Won't Stop Humming

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

If the noise persists, it is better that you  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 concerns.  One common cause of this is a failing blower motor or fan, which can make a grinding or screeching sound. Another possible 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 better to get in touch with a heating and cooling specialist.

8. My Furnace Won't Start

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 working. Then, see if the circuit breaker or fuse controlling the furnace is working right. If these basic checks don't take care of 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, call a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Similar to 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 assessing your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting are a faulty igniter or malfunctioning flame sensor. Symptoms of these include the furnace continuously attempting 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 very easily fixed by HVAC professionals like the team at Watts Electric & AC.