Whether it’s a leaky furnace or if you flip the switch to start your heating system when the weather gets cold and it won’t start, common furnace problems can affect 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 essential in deciding whether you can troubleshoot on your own or if you need professional assistance. By monitoring 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 not sure about the problem or aren't equipped with the necessary skills and tools, it's best to call a professional HVAC company like Gee & Missler Heating & Air Conditioning. We can accurately pinpoint 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. My Furnace Is Leaking Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water created during the combustion process is not effectively draining away. This might be due to a clogged condensate drain line or a broken 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—escaping from the furnace.

It is important to manage water leaks immediately to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at Gee & Missler Heating & Air Conditioning is recommended to diagnose and resolve the issue effectively.

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

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

If your furnace won’t blow hot air, it's a good idea to contact a skilled HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and suggest the correct solution.

3. My Furnace Is Not Keeping Up

A common reason your furnace isn’t keeping up on a cold day is that your home doesn’t have enough insulation, which can cause heat loss and lower efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t produce enough heat to completely warm the space. A defective thermostat or ductwork problems can also result in inconsistent heating.

To deal with this, first check your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of your home. Also, look at the thermostat to ensure it’s set right and the batteries still function.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Gee & Missler Heating & 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 Is Not Working

If your furnace is not working, there are a couple of steps you can take to troubleshoot before calling a heating specialist. Ensure the thermostat is set correctly and the batteries are not dead. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the unit.

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

5. My Furnace Is Short Cycling

If your furnace is short cycling, that 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, more energy use and potential damage to your heating system.

If you suspect your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be changed regularly to ensure air flow, so if your furnace air filter is plugged with dirt you should exchange it for a clean one—and ensure 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 smart to call experts like the staff at Gee & Missler Heating & Air Conditioning. Immediate professional attention will help restore the proper functioning of your furnace and avoid additional complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical parts 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 a good idea to  employ 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 promptly to prevent further damage or potential safety hazards.  One common problem that causes this is a broken 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.

Given the complexity of furnace systems and potential risks involved, it's better 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 desired 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 resolve the problem, you can inspect 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 work, contact a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Much like 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, 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. Symptoms of these include the furnace repeatedly making an attempt 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 repaired by HVAC pros like the team at Gee & Missler Heating & Air Conditioning.