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

Regardless of the issue, understanding how your heating system works and a little bit about some typical furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional services. By observing 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 lack the necessary skills and tools, it's best to call a reputable HVAC company like Service Max Heating & Air Conditioning. We can accurately diagnose the issue and execute 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 prevalent heating problems:

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 properly draining away. This might be due to a blocked condensate drain line or a malfunctioning 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 imperative to correct water leaks quickly to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at Service Max Heating & Air Conditioning is recommended to diagnose and resolve the issue effectively.

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

Some potential 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 won’t blow hot air, it's best to contact a skilled HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and advise you on the proper 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 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 effectively warm the space. A malfunctioning thermostat or ductwork problems can also cause insufficient heating.

To handle this, first check your home’s insulation level and make sure it’s enough to insulate your home. Also, examine the thermostat to make sure it’s set right and the batteries still function.

If the problem continues, consider calling an experienced HVAC company, such as Service Max Heating & Air Conditioning, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting 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 pro. Make sure the thermostat is set right and the batteries are good. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the system.

If there is power but no heat, the problem may lie with the ignition system or gas supply. In that case, it's better to consult an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, it 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 lead to inefficiency, increased energy consumption and potential damage to your heating system.

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 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, check 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 Service Max Heating & Air Conditioning. Immediate professional attention will help restore the proper functioning of your furnace and prevent more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

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

If the noise doesn't go away, it is a good idea to  employ a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is producing a persistent 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 broken blower motor or fan, which can make a grinding or screeching sound. Another common 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 safer 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 preferred temperature, is in heating mode and the batteries are functioning. Then, check if the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't resolve the problem, you can examine 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 work, contact an expert for furnace repair.

9. My Furnace Is Not Igniting

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 out the air filter and taking a peek at your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting could be a faulty igniter or faulty flame sensor. Indications of these include the furnace continually trying 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 addressed by HVAC professionals like the team at Service Max Heating & Air Conditioning.