Whether it’s a leaky furnace or if you flick the switch to start your heating system in the fall and it won’t start, common furnace problems can affect your home at any moment.

Regardless of the cause, learning 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 support. By observing the furnace's behavior, listening for peculiar 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 an experienced HVAC company like Fire & Ice HVAC. We can accurately identify the issue and complete the required repairs or maintenance, so we can get your furnace up and running ASAP.

Here's more about what causes a furnace to leak water and eight other common heating problems:

1. My Furnace Is Leaking Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water produced during the combustion process is not effectively draining away. This may 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—leaking out of the furnace.

It is important to manage water leaks immediately to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Fire & Ice HVAC is recommended to diagnose and resolve the issue properly.

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 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 will not blow hot air, it's better to contact a professional HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend the correct solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home doesn’t have enough insulation, which can cause heat loss and reduced efficiency. Another reason your furnace is falling short is because it’s not big enough for your home, so it can’t make enough heat to completely warm the space. A broken thermostat or ductwork problems can also cause insufficient heating.

To address this, first look at your home’s insulation level and make sure it’s enough to insulate your home. Also, look at the thermostat to make sure it’s set right and the batteries still function.

If the problem won’t go away, consider calling an experienced HVAC company, such as Fire & Ice HVAC, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting your thermostat settings.

4. My Furnace Is Not Working

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a pro. Ensure the thermostat is set properly 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 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 an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, it means it is turning on and off often at short intervals instead of running in regular cycles like it ought to. This can lead to 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 changed 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 ensure it is pointing in the right direction. If that doesn’t do the trick, 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 staff at Fire & Ice HVAC. Immediate professional attention will help restore the proper functioning of your furnace and reduce the chance of additional complications and high energy bills.

6. My Furnace Hums All the Time

If your furnace is making a humming noise, it often is a symptom of problems with the electrical hardware or the blower motor. For this reason, if you detect your furnace making a humming noise, it is important to take action.

If the noise persists, it is a good idea to  get in touch with a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is producing a persistent loud noise, it's important to address 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 generate a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Given 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 will not turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse controlling the furnace is functioning properly. 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

Like a a furnace not turning on at all, a furnace that isn’t igniting can be caused by a clogged air filter or a tripped circuit breaker. So, checking out the air filter and looking over your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting are a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace repeatedly trying 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 easily addressed by HVAC specialists like the team at Fire & Ice HVAC.