Whether it’s a leaky furnace or if you flip the switch to turn on 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 issue, understanding how your heating system works and a little bit about some frequent furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional support. By observing the furnace's behavior, listening for unusual noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're uncertain about the problem or lack the necessary skills and tools, it's best to call an experienced HVAC company like Phelps Heating & Cooling, Inc.. 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 problems:

1. The Furnace Is Leaking

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

It is important to manage water leaks promptly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at Phelps Heating & Cooling, Inc. is recommended to diagnose and resolve the issue effectively.

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

Some possible 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 precaution.

If your furnace will not blow hot air, it's better to contact a skilled HVAC technician to diagnose and fix the problem. They can give an accurate assessment and suggest 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 cause heat loss and lower efficiency. Another reason your furnace is having difficulties is because it’s not big enough for your home, so it can’t generate enough heat to adequately warm the space. A defective thermostat or ductwork problems can also cause insufficient heating.

To handle this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, look at the thermostat to ensure it’s set right and the batteries are working.

If the problem won’t go away, consider consulting with an experienced HVAC company, such as Phelps Heating & Cooling, Inc., who can inspect 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 a few steps you can take to troubleshoot before phoning a professional. Check if the thermostat is set correctly and the batteries are not dead. 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 best to contact an experienced HVAC professional for diagnosis and repair.

5. My Furnace Turns On and Off

If your furnace is short cycling, that means it is turning on and off multiple times at short intervals as opposed to running in regular cycles like it ought to. This can lead to inefficiency, higher energy bills and potential damage to your furnace.

If you think your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be changed on a regular basis 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. Second, 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 Phelps Heating & Cooling, Inc.. 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

When your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical parts or the blower motor. For this reason, if you hear your furnace making a humming noise, it is critical to take action.

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

7. My Furnace Is Noisy

If your furnace is producing a constant loud noise, it's important to address the issue right away to prevent further damage or potential safety concerns.  One common reason is a broken blower motor or fan, which can create a grinding or screeching sound. Another possible 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 better to contact a heating and cooling specialist.

8. My Furnace Is Not Turning 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 working. Then, check if the circuit breaker or fuse controlling the furnace is sending power to the unit. If these basic checks don't address the problem, you can examine the furnace's power switch or emergency shutoff switch to make sure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t get the job done, call an expert for furnace repair.

9. My Furnace Is on but Not Igniting

Like a a furnace that won't turn on at all, a furnace that isn’t igniting can be caused by 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 likely causes of a furnace not igniting are a faulty igniter or nonfunctional flame sensor. Symptoms of these include the furnace continually attempting to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be very easily solved by HVAC specialists like the team at Phelps Heating & Cooling, Inc..