Whether it’s a leaky furnace or if you flick the switch to power up 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 issue, knowing 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 services. By noting 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 aren't equipped with the necessary skills and tools, it's best to call a reputable HVAC company like Stieferman Heating Company Inc. We can accurately diagnose the issue and perform 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 frequent heating issues:

1. My Furnace Is Leaking Water

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

It is important to correct water leaks quickly to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Stieferman Heating Company Inc is recommended to diagnose and resolve the issue successfully.

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

Some possible causes for a furnace blowing cold air or not blowing hot air are 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 measure.

If your furnace does not blow hot air, it's better to contact a skilled HVAC tech to diagnose and fix the problem. They can give an accurate assessment and recommend 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 is lacking insulation, which can cause heat loss and lower efficiency. Another reason your furnace is having difficulties is because it’s not powerful enough for your home, so it can’t make enough heat to effectively warm the space. A defective thermostat or ductwork problems can also cause uneven heating.

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

If the problem continues, consider contacting an experienced HVAC company, such as Stieferman Heating Company Inc, who can look over your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or changing your thermostat settings.

4. My Furnace Is Not Working

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a pro. Make sure the thermostat is set properly 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 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 better to reach out to an experienced HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, this means it is turning on and off often at short intervals rather than running in regular cycles like it ought to. This can lead to inefficiency, increased energy consumption and potential damage to your furnace.

If you suspect your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be exchanged regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and make sure it is pointing in the right direction. Second, look at your thermostat and look to see if  it’s set right and the batteries are good.

If those two things don’t work, it’s best to call experts like the crew at Stieferman Heating Company Inc. Prompt professional attention will help restore the proper functioning of your furnace and avoid further 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 symptom of a malfunction with the electrical hardware or the blower motor. For this reason, if you hear your furnace making a humming noise, it is crucial to take action.

If the noise continues, it is a good idea to  get in touch with a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is emitting a consistent loud noise, it's important to handle the issue right away to prevent further damage or potential safety risks.  One common reason is a broken blower motor or fan, which can make a grinding or screeching sound. Another possible 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 better to contact 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 desired temperature, is in heating mode and the batteries are working. Then, see if the circuit breaker or fuse that controls the furnace is sending power to the unit. If these basic checks don't address the problem, you can check 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 do the job, phone a heating specialist for furnace repair.

9. My Furnace Is 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 assessing your circuit breakers are a good place to start.

Other common causes of a furnace not igniting include a faulty igniter or malfunctioning flame sensor. Indications of these include the furnace continually trying 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 easily repaired by HVAC professionals like the team at Stieferman Heating Company Inc.