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 affect your home at any moment.

Regardless of the issue, learning how your heating system works and a little bit about some common furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional assistance. 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 Rescue Heating & Air. We can accurately diagnose 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 prevalent heating dilemmas:

1. The Furnace Is Leaking

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

It is important to deal with water leaks quickly to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Rescue Heating & Air is recommended to diagnose and resolve the issue successfully.

2. My Furnace Makes Cold Air/Lack of Heat

Some possible 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 mechanism.

If your furnace does not blow hot air, it's better to contact a skilled HVAC specialist to diagnose and fix the problem. They can offer an accurate assessment and recommend 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 cause heat loss and lower 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 effectively warm the space. A broken thermostat or ductwork problems can also produce inconsistent 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 ensure it’s set right and the batteries aren’t dead.

If the problem lingers, consider consulting with an experienced HVAC company, such as Rescue Heating & Air, who can assess 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 some steps you can take to troubleshoot before contacting a heating specialist. Make sure the thermostat is set right and the batteries are fresh. If the furnace still doesn't power on, check the circuit breaker or fuse box to ensure power is reaching the system.

If there is power but your furnace won't blow hot air, 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 professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, that means it is turning on and off often at short intervals as opposed to running in regular cycles like it ought to. This can cause inefficiency, more energy use and potential damage to your heating system.

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be changed when they are dirty to ensure air flow, so if your furnace air filter is plugged with dirt 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, check your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s best to call experts like the team at Rescue Heating & Air. Quick professional attention will help restore the proper functioning of your furnace and reduce the chance of further complications and high energy bills.

6. My Furnace Hums All the Time

If your furnace is making a humming noise, it often is an indication of problems with the electrical components or the blower motor. Therefore, if you detect your furnace making a humming noise, it is critical to take action.

If the noise doesn't go away, it is best to  employ a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is making a constant loud noise, it's important to address the issue promptly to prevent further damage or potential safety risks.  One common cause of this is a failing blower motor or fan, which can create a grinding or screeching sound. Another common 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 best to get in touch with a heating and cooling specialist.

8. My Furnace Can't Turn On

If your furnace won't turn on, make sure the thermostat is set to the right temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse that goes to the furnace is working right. If these basic checks don't resolve 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 do the job, contact an expert for furnace repair.

9. My Furnace Is Not Igniting

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

Other potential causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace continually trying to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be simply repaired by HVAC pros like the team at Rescue Heating & Air.