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

Regardless of the issue, knowing how your heating system works and a little bit about some frequent furnace problems is vital 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 unsure about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like Diedrick's Heating and Air Conditioning. 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 prevalent heating issues:

1. My Furnace Is Leaking Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water released during the combustion process is not effectively draining away. This may be due to a blocked condensate drain line or a broken condensate pump. Another likely 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 necessary to address water leaks quickly to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Diedrick's Heating and Air Conditioning is recommended to diagnose and resolve the issue effectively.

2. My Furnace Is Blowing Cold Air/Lack of Heat

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 better to contact a trained HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and suggest the appropriate 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 doesn’t have enough insulation, which can cause heat loss and lower 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 broken thermostat or ductwork problems can also cause uneven heating.

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

If the problem lingers, consider consulting with an experienced HVAC company, such as Diedrick's Heating and 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 couple of steps you can take to troubleshoot before contacting a professional. Ensure the thermostat is set right and the batteries are not dead. If the furnace still doesn't power on, check the circuit breaker or fuse box to make sure 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 reach out to a seasoned HVAC technician for diagnosis and repair.

5. My Furnace Turns On and Off

If your furnace is short cycling, it means it is turning on and off often at short intervals rather than running in regular cycles like it is designed to do. This can result in inefficiency, increased energy consumption and potential damage to your heating system.

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be changed on a regular basis to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and make sure it is pointing in the right direction. Second, 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 best to call experts like the crew at Diedrick's Heating and Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and prevent additional complications and high energy bills.

6. My Furnace Hums All the Time

If your furnace is making a humming noise, it often is a symptom of problems with the electrical elements or the blower motor. Because of this, if you detect your furnace making a humming noise, it is important to take action.

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

7. My Furnace Is Noisy

If your furnace is producing 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 malfunctioning blower motor or fan, which can make 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 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 working. Then, verify that the circuit breaker or fuse that controls the furnace is working right. If these basic checks don't resolve the problem, you can inspect 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 get the job done, contact a professional for furnace repair.

9. My Furnace Is on but Not Igniting

Like a a furnace not turning on at all, a furnace that isn’t igniting can be the result of a dirty 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 could be a faulty igniter or faulty flame sensor. Signs of these include the furnace continuously trying 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 repaired by HVAC pros like the team at Diedrick's Heating and Air Conditioning.