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 problem, knowing 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 noting 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 not sure about the problem or lack the necessary skills and tools, it's best to call a professional HVAC company like Comfort Concepts Heating & Air Conditioning. We can accurately identify 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 frequent heating dilemmas:

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 effectively draining away. This might be due to a plugged 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 necessary to address water leaks immediately to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at Comfort Concepts Heating & Air Conditioning is recommended to diagnose and resolve the issue effectively.

2. My Furnace Is Blowing Cold Air/Lack of Heat

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 blocked air filter, or a malfunctioning heating element. It is also possible your furnace is overheating and shutting off as a safety measure.

If your furnace won’t blow hot air, it's a good idea to contact a skilled HVAC specialist to diagnose and fix the problem. They can give an accurate assessment and suggest the appropriate solution.

3. My Furnace Can't Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can lead to heat loss and decreased 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 effectively warm the space. A defective thermostat or ductwork problems can also produce uneven heating.

To deal with this, first look at your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of 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 Comfort Concepts Heating & Air Conditioning, who can look over 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 some steps you can take to troubleshoot before contacting a heating specialist. Check if the thermostat is set correctly and the batteries are good. If the furnace still doesn't power on, check the circuit breaker or fuse box to ensure power is reaching the furnace.

If there is power but no heat, the problem may rest with the ignition system or gas supply. In that case, it's better to consult an experienced 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 frequently at short intervals rather than running in regular cycles like it is designed to do. This can result in inefficiency, higher energy bills and potential damage to your furnace.

If you suspect your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged when they are dirty to ensure air flow, so if your furnace air filter is clogged with debris 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 look to see if  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 Comfort Concepts Heating & Air Conditioning. Quick 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

If your furnace is making a humming noise, it often is an indication of a malfunction 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 continues, it is best to  contact a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is emitting a persistent 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 malfunctioning blower motor or fan, which can make a grinding or screeching sound. Another common cause is a loose or worn-out belt that may produce a squealing or rattling noise.

Due to 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 Won't Start

If your furnace won't turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are functioning. Then, see if the circuit breaker or fuse controlling the furnace is sending power to the unit. If these basic checks don't take care of the problem, you can inspect the furnace's power switch or emergency shutoff switch to make sure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t get the job done, contact an expert for furnace repair.

9. My Furnace Is Not Igniting

Much like a furnace not turning on at all, a furnace that isn’t igniting can be the result of a dirty air filter or a tripped circuit breaker. So, inspecting the air filter and taking a peek at your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Indications of these include the furnace continuously making an attempt 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 repaired by HVAC specialists like the team at Comfort Concepts Heating & Air Conditioning.