Whether it’s a leaky furnace or if you throw the switch to power up your heating system when the weather gets cold and it won’t start, common furnace problems can impact your home at any moment.

Regardless of the cause, understanding 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 assistance. By watching 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 unsure about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like Total Assurance AC & Heating. We can accurately diagnose 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 frequent heating issues:

1. The Furnace Is Leaking

A furnace can leak water for many reasons. One possibility is a condensate leak, where the water produced during the combustion process is not properly draining away. This could be due to a plugged condensate drain line or a malfunctioning 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—coming out of the furnace.

It is necessary to deal with water leaks immediately to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at Total Assurance AC & Heating is recommended to diagnose and resolve the issue successfully.

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

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

If your furnace will not blow hot air, it's a good idea to contact a skilled HVAC technician to diagnose and fix the problem. They can offer 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 lead to heat loss and lower efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t make enough heat to adequately warm the space. A malfunctioning thermostat or ductwork problems can also result in insufficient heating.

To deal with this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, check the thermostat to make sure it’s set right and the batteries still function.

If the problem lingers, consider consulting with an experienced HVAC company, such as Total Assurance AC & Heating, 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 Won't Work

If your furnace is not working, there are a couple of steps you can take to troubleshoot before contacting a professional. Make sure the thermostat is set right and the batteries are not dead. If the furnace still doesn't start, check the circuit breaker or fuse box to make sure power is reaching the unit.

If there is power but your furnace won't blow hot air, the problem may rest with the ignition system or gas supply. In that case, it's best to reach out to a knowledgeable 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 frequently at short intervals instead of running in regular cycles like it is designed to do. This can lead to inefficiency, increased energy consumption and potential damage to your furnace.

If you think 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 be sure 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 best to call experts like the staff at Total Assurance AC & Heating. Immediate professional attention will help restore the proper functioning of your furnace and reduce the chance of more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

If your furnace is making a humming noise, it often is a sign of problems with the electrical parts or the blower motor. Therefore, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is better that you  get in touch with a professional HVAC technician.

7. My Furnace Is Noisy

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

Because of 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 good. Then, see if the circuit breaker or fuse that controls the furnace is sending power to the unit. 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 get the job done, call a professional 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 clogged air filter or a tripped circuit breaker. So, examining the air filter and looking over your circuit breakers are a good place to start.

Other common causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Indications of these include the furnace continually 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 fixed by HVAC professionals like the team at Total Assurance AC & Heating.