Whether it’s a leaky furnace or if you flip the switch to start 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, learning how your heating system works and a little bit about some frequent furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional support. 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 don't have the necessary skills and tools, it's best to call an experienced HVAC company like Fleming Heating & Air Conditioning Inc. 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 many reasons. One possibility is a condensate leak, where the water created during the combustion process is not properly draining away. This could be due to a blocked condensate drain line or a broken condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can be responsible for water—as well as dangerous gases—leaking out of the furnace.

It is important to address water leaks promptly to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Fleming Heating & Air Conditioning Inc is recommended to diagnose and resolve the issue successfully.

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

Some possible 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 also may be your furnace is overheating and shutting off as a safety mechanism.

If your furnace will not blow hot air, it's best to contact a professional HVAC specialist to diagnose and fix the problem. They can give an accurate assessment and advise you on the correct solution.

3. My Furnace Is Not Keeping Up

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

To correct this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, examine the thermostat to make sure it’s set right and the batteries are working.

If the problem lingers, consider calling an experienced HVAC company, such as Fleming Heating & Air Conditioning Inc, 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 Is Not Working

If your furnace is not working, there are a couple of steps you can take to troubleshoot before contacting a professional. Make sure the thermostat is set properly and the batteries are good. If the furnace still doesn't start, check the circuit breaker or fuse box to make sure 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 a good idea to reach out to a knowledgeable HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, this means it is turning on and off multiple times at short intervals rather than running in regular cycles like it ought to. This can result in inefficiency, increased energy consumption and potential damage to your unit.

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be changed regularly 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. If that doesn’t do the trick, 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 Fleming Heating & Air Conditioning Inc. Prompt professional attention will help restore the proper functioning of your furnace and avoid 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 symptom of problems with the electrical parts or the blower motor. Because of this, if you hear your furnace making a humming noise, it is important to take action.

If the noise continues, it is a good idea to  employ a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is emitting a constant loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety concerns.  One common reason is a failing 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 better 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 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 verify they're in the "on" position and weren’t accidentally turned off.

If those steps don’t work, contact a professional for furnace repair.

9. My Furnace Is Not Igniting

Similar to a furnace not turning on at all, a furnace that isn’t igniting can be caused by a dirty air filter or a tripped circuit breaker. So, examining the air filter and assessing your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting could be a faulty igniter or nonfunctional flame sensor. Symptoms of these include the furnace repeatedly 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 simply addressed by HVAC professionals like the team at Fleming Heating & Air Conditioning Inc.