Whether it’s a leaky furnace or if you flick the switch to turn on your heating system when the weather gets cold and it won’t start, common furnace problems can strike 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 essential in deciding whether you can troubleshoot on your own or if you need professional services. 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 Willco Air Conditioning, Refrigeration & Heating Inc.. We can accurately pinpoint the issue and complete 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 common heating problems:

1. Your Furnace Leaks Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water produced during the combustion process is not effectively draining away. This may be due to a plugged 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 important to deal with water leaks immediately to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Willco Air Conditioning, Refrigeration & Heating Inc. is recommended to diagnose and resolve the issue successfully.

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

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

If your furnace does not blow hot air, it's better to contact a professional HVAC tech to diagnose and fix the problem. They can provide an accurate assessment and suggest the appropriate solution.

3. My Furnace Struggles to Keep 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 decreased efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t make enough heat to completely warm the space. A broken thermostat or ductwork problems can also produce insufficient heating.

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

If the problem lingers, consider contacting an experienced HVAC company, such as Willco Air Conditioning, Refrigeration & Heating 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 a few steps you can take to troubleshoot before contacting a heating specialist. Make sure the thermostat is set correctly and the batteries are fresh. If the furnace still doesn't power on, check the circuit breaker or fuse box to verify power is reaching the unit.

If there is power but your furnace won't ignite, 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 Short Cycles

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

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged when they are dirty to ensure air flow, so if your furnace air filter is dirty 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 verify  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 Willco Air Conditioning, Refrigeration & Heating Inc.. 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

When your furnace is making a humming noise, it often is a symptom of problems with the electrical hardware or the blower motor. For this reason, if you detect your furnace making a humming noise, it is crucial to take action.

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

7. My Furnace Makes Loud Noises

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 hazards.  One common problem that causes this is a malfunctioning blower motor or fan, which can create a grinding or screeching sound. Another possible 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 won't turn on, make sure the thermostat is set to the preferred temperature, is in heating mode and the batteries are working. Then, see if the circuit breaker or fuse controlling the furnace is working right. If these basic checks don't fix 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, contact a heating specialist for furnace repair.

9. My Furnace Won't Ignite

Similar to a furnace that won't turn on at all, a furnace that isn’t igniting can be the result of a plugged air filter or a tripped circuit breaker. So, examining the air filter and looking over your circuit breakers are a good place to start.

Other common causes of a furnace not igniting could be a faulty igniter or malfunctioning flame sensor. Indications of these include the furnace continually attempting 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 very easily fixed by HVAC specialists like the team at Willco Air Conditioning, Refrigeration & Heating Inc..