Whether it’s a leaky furnace or if you flick the switch to turn on your heating system when it gets chilly and it won’t start, common furnace problems can impact your home at any moment.

Regardless of the cause, learning how your heating system works and a little bit about some common furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional support. By watching 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 lack the necessary skills and tools, it's best to call an experienced HVAC company like Strine's. We can accurately diagnose the issue and complete the required repairs or maintenance, so we can get your furnace ready to go ASAP.

Here's more about what causes a furnace to leak water and eight other prevalent 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 released during the combustion process is not properly draining away. This could be due to a blocked condensate drain line or a broken condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—coming out of the furnace.

It is important to correct water leaks immediately to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Strine's is recommended to diagnose and resolve the issue properly.

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 could be a malfunctioning thermostat, a problem with the pilot light or ignition system, a blocked air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety measure.

If your furnace does not blow hot air, it's a good idea 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 widespread reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can lead to heat loss and reduced efficiency. Another reason your furnace is struggling is because it’s not powerful enough for your home, so it can’t make enough heat to adequately warm the space. A broken thermostat or ductwork problems can also cause insufficient heating.

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

If the problem won’t go away, consider calling an experienced HVAC company, such as Strine's, 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 Won't Work

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a professional. Make sure the thermostat is set properly and the batteries are fresh. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the furnace.

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

5. My Furnace Short Cycles

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

If you believe your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged when they are dirty 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 best to call experts like the team at Strine's. Quick professional attention will help restore the proper functioning of your furnace and avoid additional complications and high energy bills.

6. My Furnace Hums All the Time

When your furnace is making a humming noise, it often is a sign 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 crucial to take action.

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

7. My Furnace Is Noisy

If your furnace is emitting a persistent loud noise, it's important to handle the issue promptly to prevent further damage or potential safety concerns.  One common reason is a failing blower motor or fan, which can generate a grinding or screeching sound. Another possible cause is a loose or worn-out belt that may produce a squealing or rattling noise.

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

8. My Furnace Won't Start

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 good. Then, see if the circuit breaker or fuse that goes to the furnace is functioning properly. If these basic checks don't fix 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, call a professional 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 plugged air filter or a tripped circuit breaker. So, checking out the air filter and assessing your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting are a faulty igniter or malfunctioning flame sensor. Indications of these include the furnace repeatedly 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 very easily fixed by HVAC pros like the team at Strine's.