Whether it’s a leaky furnace or if you flip the switch to start 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, understanding how your heating system works and a little bit about some common furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional assistance. By watching 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 reputable HVAC company like Diedrick's Heating and Air Conditioning. We can accurately identify the issue and perform 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 prevalent heating problems:

1. Your Furnace Leaks 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 properly draining away. This might be due to a blocked condensate drain line or a malfunctioning 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 imperative to address water leaks promptly to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at Diedrick's Heating and Air Conditioning is recommended to diagnose and resolve the issue effectively.

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

Some likely 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 also may be your furnace is overheating and shutting off as a safety measure.

If your furnace will not blow hot air, it's a good idea to contact a trained HVAC tech to diagnose and fix the problem. They can give an accurate assessment and advise you on the appropriate solution.

3. My Furnace Is Not Keeping Up

A frequent reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can result in heat loss and lower efficiency. Another reason your furnace is having difficulties is because it’s too small 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 handle this, first look at your home’s insulation level and make sure it’s enough to protect your home. Also, check the thermostat to make sure it’s set right and the batteries are working.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Diedrick's Heating and Air Conditioning, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying your thermostat settings.

4. My Furnace Won't Work

If your furnace is not working, there are a few steps you can take to troubleshoot before contacting a professional. Check if the thermostat is set correctly and the batteries are fresh. If the furnace still doesn't start, check the circuit breaker or fuse box to verify power is reaching the system.

If there is power but no heat, the problem may be with the ignition system or gas supply. In that case, it's best to reach out to an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, that means it is turning on and off frequently at short intervals instead of running in regular cycles like it should. This can cause inefficiency, higher energy bills and potential damage to your unit.

If you think your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged 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, check 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 team at Diedrick's Heating and Air Conditioning. Quick 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

When your furnace is making a humming noise, it often is a sign of a malfunction with the electrical hardware or the blower motor. Therefore, if you notice your furnace making a humming noise, it is important to take action.

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

7. My Furnace Is Making a Loud Noise

If your furnace is making a persistent loud noise, it's important to handle the issue quickly to prevent further damage or potential safety risks.  One common reason is a malfunctioning blower motor or fan, which can generate a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may produce a squealing or rattling noise.

Because of the complexity of furnace systems and potential risks involved, it's best to contact 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, check if the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't resolve the problem, you can examine 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 a professional for furnace repair.

9. My Furnace Is Not Igniting

Like a a furnace that will not 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 looking over your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting could be a faulty igniter or nonfunctional flame sensor. Symptoms 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 simply solved by HVAC pros like the team at Diedrick's Heating and Air Conditioning.