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

Regardless of the cause, 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 assistance. By monitoring the furnace's behavior, listening for strange 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 professional HVAC company like Olde Towne Heating & Air. We can accurately identify 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 common heating dilemmas:

1. The Furnace Is Leaking

A furnace can leak water for a number of 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 be responsible for water—as well as dangerous gases—escaping from the furnace.

It is imperative to address water leaks immediately to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Olde Towne Heating & Air is recommended to diagnose and resolve the issue properly.

2. My Furnace Is Blowing Cold Air/Lack of Heat

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 could also be 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 trained HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and advise you on the correct solution.

3. My Furnace Struggles to Keep 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 reduced efficiency. Another reason your furnace is falling short 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 result in insufficient heating.

To correct 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 are working.

If the problem continues, consider consulting with an experienced HVAC company, such as Olde Towne Heating & Air, who can look over your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying 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 contacting a heating specialist. Check if the thermostat is set properly and the batteries are good. If the furnace still doesn't start, check the circuit breaker or fuse box to ensure power is reaching the system.

If there is power but no heat, the problem may rest with the ignition system or gas supply. In that case, it's best to consult a knowledgeable HVAC technician 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 often at short intervals instead of running in regular cycles like it should. This can cause inefficiency, higher energy bills and potential damage to your furnace.

If you suspect your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be switched out 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 be sure it is pointing in the right direction. If that doesn’t do the trick, go to 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 team at Olde Towne Heating & Air. Quick 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 Hums All the Time

If your furnace is making a humming noise, it often is an indication of a malfunction with the electrical components or the blower motor. Therefore, if you detect your furnace making a humming noise, it is crucial to take action.

If the noise doesn't go away, it is a good idea to  get in touch with a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is producing a persistent loud noise, it's important to address the issue promptly to prevent further damage or potential safety risks.  One common reason is a failing blower motor or fan, which can create 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 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 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 resolve the problem, you can inspect 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, call an expert for furnace repair.

9. My Furnace Won't Ignite

Much like a furnace not turning on at all, a furnace that isn’t igniting can be caused by a dirty air filter or a tripped circuit breaker. So, checking the air filter and taking a peek at 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. Signs 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 easily solved by HVAC professionals like the team at Olde Towne Heating & Air.