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

Regardless of the issue, learning how your heating system works and a little bit about some common furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional assistance. 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 not sure about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like McFadden Heating & Cooling. We can accurately diagnose the issue and execute 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 dilemmas:

1. The Furnace Is Leaking

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water released during the combustion process is not completely draining away. This could be due to a plugged condensate drain line or a broken condensate pump. Another potential 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 imperative to correct water leaks promptly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at McFadden Heating & Cooling 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 clogged air filter, or a malfunctioning heating element. It is also possible 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 trained HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend the correct solution.

3. My Furnace Is Not Keeping Up

A frequent 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 reduced efficiency. Another reason your furnace is falling short is because it’s too small for your home, so it can’t produce enough heat to adequately warm the space. A broken thermostat or ductwork problems can also produce uneven heating.

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

If the problem continues, consider calling an experienced HVAC company, such as McFadden Heating & Cooling, who can inspect 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 couple of steps you can take to troubleshoot before contacting a pro. Make sure the thermostat is set right and the batteries are not dead. If the furnace still doesn't turn on, check the circuit breaker or fuse box to verify power is reaching the system.

If there is power but no heat, the problem may be 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 Short Cycles

If your furnace is short cycling, this means it is turning on and off multiple times at short intervals rather than running in regular cycles like it ought to. This can cause inefficiency, higher energy bills and potential damage to your unit.

If you suspect your furnace is short cycling, the first step is to look at 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 dirty you should exchange it for a clean one—and be sure it is pointing in the right direction. Second, look at your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s smart to call experts like the staff at McFadden Heating & Cooling. Immediate professional attention will help restore the proper functioning of your furnace and avoid more complications and high energy bills.

6. My Furnace Won't Stop Humming

If your furnace is making a humming noise, it often is a sign of a malfunction with the electrical hardware or the blower motor. Because of this, if you notice your furnace making a humming noise, it is important to take action.

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

7. My Furnace Makes Loud Noises

If your furnace is making a persistent loud noise, it's important to handle 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 make 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 safer to consult with a heating and cooling specialist.

8. My Furnace Can't Turn On

If your furnace will not 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 that controls the furnace is working right. If these basic checks don't take care of the problem, you can examine the furnace's power switch or emergency shutoff switch to ensure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t work, phone a heating specialist for furnace repair.

9. My Furnace Is on but Not Igniting

Similar to a furnace that won't turn on at all, a furnace that isn’t igniting can be caused by a clogged 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 likely causes of a furnace not igniting are a faulty igniter or malfunctioning flame sensor. Symptoms of these include the furnace continuously making an attempt to ignite without success, an absence of heat production or the furnace is making a burning or gas smell. Both of these issues can be simply solved by HVAC professionals like the team at McFadden Heating & Cooling.