Whether it’s a leaky furnace or if you flip the switch to power up your heating system in the fall and it won’t start, common furnace problems can strike your home at any moment.

Regardless of the problem, 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 support. By watching 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 uncertain about the problem or don't have the necessary skills and tools, it's best to call an experienced HVAC company like GV Heating & Air. We can accurately diagnose the issue and perform 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 common heating issues:

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 effectively draining away. This may be due to a blocked condensate drain line or a failing condensate pump. Another possible cause of water leakage from a furnace is a cracked heat exchanger, which can lead to water—as well as dangerous gases—coming out of the furnace.

It is important to deal with water leaks quickly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at GV Heating & Air is recommended to diagnose and resolve the issue effectively.

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

Some possible causes for a furnace blowing cold air or not blowing hot air include 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 better to contact a professional HVAC tech to diagnose and fix the problem. They can give 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 is lacking insulation, which can result in heat loss and lower efficiency. Another reason your furnace is falling short is because it’s not big enough for your home, so it can’t make enough heat to effectively warm the space. A broken thermostat or ductwork problems can also result in uneven 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 see if it’s set right and the batteries are working.

If the problem continues, consider calling an experienced HVAC company, such as GV Heating & Air, who can inspect 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 phoning a professional. Make sure the thermostat is set properly and the batteries are fresh. If the furnace still doesn't power on, check the circuit breaker or fuse box to ensure power is reaching the unit.

If there is power but your furnace won't ignite, the problem may rest with the ignition system or gas supply. In that case, it's better to consult a knowledgeable 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 frequently at short intervals as opposed to running in regular cycles like it is designed to do. This can cause 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 changed 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 make 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 crew at GV Heating & Air. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of further complications and high energy bills.

6. My Furnace Won't Stop Humming

When your furnace is making a humming noise, it often is a sign of problems with the electrical parts or the blower motor. Therefore, if you detect your furnace making a humming noise, it is critical to take action.

If the noise persists, it is best to  employ a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a persistent loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety concerns.  One common cause of this 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 emit a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's better to get a hold of 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 right temperature, is in heating mode and the batteries are functioning. 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 check 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 do the job, call an expert for furnace repair.

9. My Furnace Won't Ignite

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

Other common causes of a furnace not igniting include a faulty igniter or faulty flame sensor. Signs of these include the furnace continuously making an attempt 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 pros like the team at GV Heating & Air.