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

Regardless of the cause, knowing how your heating system works and a little bit about some typical furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional services. By monitoring 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 professional HVAC company like Farris Heating & Air. We can accurately diagnose the issue and complete 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 frequent heating problems:

1. My Furnace Is Leaking Water

A furnace can leak water for a number of reasons. One possibility is a condensate leak, where the water created during the combustion process is not completely draining away. This might be due to a clogged condensate drain line or a broken condensate pump. Another possible cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—coming out of the furnace.

It is necessary to address water leaks immediately to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Farris Heating & Air is recommended to diagnose and resolve the issue successfully.

2. My Furnace Makes Cold Air/Lack of Heat

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 could also be your furnace is overheating and shutting off as a safety mechanism.

If your furnace won’t blow hot air, it's better to contact a skilled HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and suggest the proper solution.

3. My Furnace Is Not Keeping Up

A common reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can result in heat loss and decreased efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t make enough heat to adequately warm the space. A broken thermostat or ductwork problems can also cause uneven heating.

To correct this, first check your home’s insulation level and make sure it’s enough to protect your home. Also, look at the thermostat to see if it’s set right and the batteries aren’t dead.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Farris Heating & Air, 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 some steps you can take to troubleshoot before contacting a pro. Check if the thermostat is set right and the batteries are not dead. If the furnace still doesn't turn on, check the circuit breaker or fuse box to verify power is reaching the system.

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 contact a seasoned HVAC professional for diagnosis and repair.

5. My Furnace Short Cycles

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

If you suspect your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be switched out on a regular basis 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. Next, go to your thermostat and make sure  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 Farris Heating & Air. Quick 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

Whenever your furnace is making a humming noise, it often is a symptom of an issue with the electrical elements or the blower motor. For this reason, 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  contact a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a constant loud noise, it's important to handle the issue quickly to prevent further damage or potential safety risks.  One common cause of this is a failing blower motor or fan, which can generate 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 safer to contact 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 working. Then, check if the circuit breaker or fuse controlling the furnace is working right. If these basic checks don't resolve the problem, you can check the furnace's power switch or emergency shutoff switch to verify they're in the "on" position and weren’t accidentally turned off.

If those steps don’t do the job, contact a professional 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 caused by 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 common causes of a furnace not igniting could be a faulty igniter or nonfunctional flame sensor. Indications of these include the furnace continually attempting to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be easily fixed by HVAC pros like the team at Farris Heating & Air.