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 strike your home at any moment.

Regardless of the cause, knowing 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 support. By observing 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 unsure about the problem or aren't equipped with the necessary skills and tools, it's best to call an experienced HVAC company like Stephen Hurst Pack Heating and Cooling. We can accurately identify 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 frequent heating issues:

1. Your Furnace Leaks Water

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 completely draining away. This could be due to a clogged condensate drain line or a malfunctioning condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can be responsible for water—as well as dangerous gases—escaping from the furnace.

It is necessary to correct water leaks promptly to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Stephen Hurst Pack Heating and Cooling is recommended to diagnose and resolve the issue successfully.

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

Some likely 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 measure.

If your furnace won’t blow hot air, it's best to contact a trained HVAC tech to diagnose and fix the problem. They can provide an accurate assessment and recommend the proper 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 falling short is because it’s not powerful enough for your home, so it can’t produce enough heat to completely 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 see if it’s set right and the batteries are working.

If the problem continues, consider consulting with an experienced HVAC company, such as Stephen Hurst Pack Heating and Cooling, who can assess 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 a few steps you can take to troubleshoot before contacting a professional. Check if the thermostat is set right and the batteries are good. If the furnace still doesn't start, 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 be with the ignition system or gas supply. In that case, it's better to reach out to an experienced HVAC technician 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 should. This can result in inefficiency, higher energy bills and potential damage to your unit.

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be changed when they are dirty to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and ensure it is pointing in the right direction. Next, go to your thermostat and look to see if  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 Stephen Hurst Pack Heating and Cooling. Prompt 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 a sign of a malfunction with the electrical hardware or the blower motor. Therefore, if you notice your furnace making a humming noise, it is critical to take action.

If the noise doesn't go away, it is better that you  contact a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is emitting a constant loud noise, it's important to handle the issue quickly to prevent further damage or potential safety hazards.  One common cause of this is a broken blower motor or fan, which can create a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may make a squealing or rattling noise.

Due to 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, verify that the circuit breaker or fuse that goes to the furnace is sending power to the unit. If these basic checks don't resolve the problem, you can examine 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 Is on but Not Igniting

Similar to a furnace that will not on at all, a furnace that isn’t igniting can be the result of a clogged air filter or a tripped circuit breaker. So, inspecting 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 faulty flame sensor. Signs 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 easily solved by HVAC professionals like the team at Stephen Hurst Pack Heating and Cooling.