Whether it’s a leaky furnace or if you throw the switch to start your heating system in the fall and it won’t start, common furnace problems can affect your home at any moment.

Regardless of the problem, understanding 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 support. By noting 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 Pliescott HVAC Services LLC. We can accurately identify the issue and execute 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 several reasons. One possibility is a condensate leak, where the water produced during the combustion process is not completely draining away. This might 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 lead to water—as well as dangerous gases—escaping from the furnace.

It is necessary to correct water leaks immediately to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Pliescott HVAC Services LLC is recommended to diagnose and resolve the issue successfully.

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

Some possible 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 precaution.

If your furnace will not blow hot air, it's better to contact a trained HVAC tech to diagnose and fix the problem. They can give an accurate assessment and advise you on the correct 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 doesn’t have enough insulation, which can lead to heat loss and reduced efficiency. Another reason your furnace is having difficulties is because it’s too small for your home, so it can’t produce enough heat to effectively warm the space. A defective thermostat or ductwork problems can also cause insufficient heating.

To handle this, first look at your home’s insulation level and make sure it’s enough to protect your home. Also, look at the thermostat to ensure it’s set right and the batteries aren’t dead.

If the problem continues, consider contacting an experienced HVAC company, such as Pliescott HVAC Services LLC, 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 couple of steps you can take to troubleshoot before phoning a professional. Check if the thermostat is set properly and the batteries are good. If the furnace still doesn't turn on, check the circuit breaker or fuse box to verify power is reaching the unit.

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 consult an experienced HVAC professional for diagnosis and repair.

5. My Furnace Short Cycles

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 should. This can lead to inefficiency, increased energy consumption and potential damage to your unit.

If you think your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be switched out regularly 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. Next, 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 Pliescott HVAC Services LLC. Immediate professional attention will help restore the proper functioning of your furnace and prevent additional complications and high energy bills.

6. My Furnace Won't Stop Humming

If your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical elements or the blower motor. Because of this, if you detect your furnace making a humming noise, it is critical to take action.

If the noise persists, it is best to  employ 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 promptly to prevent further damage or potential safety risks.  One common problem that causes this is a broken blower motor or fan, which can make a grinding or screeching sound. Another common cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's safer to get in touch with a heating and cooling specialist.

8. My Furnace Is Not Turning On

If your furnace refuses to 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 controlling 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 verify they're in the "on" position and weren’t accidentally turned off.

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

9. My Furnace Won't Ignite

Like a a furnace that will not on at all, a furnace that isn’t igniting can be the result of a clogged air filter or a tripped circuit breaker. So, checking the air filter and assessing your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting are a faulty igniter or faulty flame sensor. Symptoms of these include the furnace continually making an attempt to ignite without success, a lack 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 Pliescott HVAC Services LLC.