Whether it’s a leaky furnace or if you flick the switch to turn on your heating system when it gets chilly 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 essential in deciding whether you can troubleshoot on your own or if you need professional services. By monitoring 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 uncertain about the problem or don't have the necessary skills and tools, it's best to call an experienced HVAC company like Giordanos Heating and Air Conditioning. We can accurately diagnose the issue and execute 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 issues:

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 produced during the combustion process is not effectively draining away. This might be due to a plugged condensate drain line or a failing condensate pump. Another likely 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 address water leaks promptly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at Giordanos Heating and Air Conditioning is recommended to diagnose and resolve the issue effectively.

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

Some potential 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 plugged 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 a good idea to contact a trained HVAC specialist to diagnose and fix the problem. They can offer an accurate assessment and recommend the correct 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 doesn’t have enough insulation, which can lead to 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 produce enough heat to completely warm the space. A defective thermostat or ductwork problems can also cause insufficient heating.

To address this, first assess 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 aren’t dead.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Giordanos Heating and Air Conditioning, 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 Isn't Running at All

If your furnace is not working, there are a few steps you can take to troubleshoot before phoning a heating specialist. 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 make sure power is reaching the furnace.

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 technician for diagnosis and repair.

5. My Furnace Short Cycles

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 cause inefficiency, increased energy consumption and potential damage to your heating system.

If you think your furnace is short cycling, the first step is to check 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 dirty you should exchange it for a clean one—and ensure it is pointing in the right direction. Second, 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 staff at Giordanos Heating and Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and avoid further 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 components or the blower motor. Because of this, if you notice your furnace making a humming noise, it is important to take action.

If the noise continues, it is better that you  contact a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is producing a constant loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety risks.  One common cause of this is a broken 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.

Given the complexity of furnace systems and potential risks involved, it's safer to consult with a heating and cooling specialist.

8. My Furnace Can't Turn 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, verify that the circuit breaker or fuse that controls the furnace is functioning properly. If these basic checks don't take care of 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, phone a heating specialist 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 caused by a clogged 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 common causes of a furnace not igniting are a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace continuously making an attempt to ignite without success, an absence of heat production or the furnace is making a burning or gas smell. Both of these issues can be easily addressed by HVAC professionals like the team at Giordanos Heating and Air Conditioning.