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 cause, learning 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 noting the furnace's behavior, listening for unusual noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're unsure about the problem or lack the necessary skills and tools, it's best to call a reputable HVAC company like Air-Right Energy Design. We can accurately pinpoint 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 common heating problems:

1. Your Furnace Leaks 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 properly draining away. This might be due to a plugged condensate drain line or a malfunctioning 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 necessary to address water leaks immediately to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at Air-Right Energy Design is recommended to diagnose and resolve the issue effectively.

2. My Furnace Blows 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 blocked air filter, or a malfunctioning heating element. It is also possible your furnace is overheating and shutting off as a safety precaution.

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 give an accurate assessment and suggest the correct 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 lacks insulation, which can cause heat loss and decreased efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t make enough heat to effectively warm the space. A defective thermostat or ductwork problems can also result in inconsistent heating.

To handle 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 aren’t dead.

If the problem continues, consider contacting an experienced HVAC company, such as Air-Right Energy Design, 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 Isn't Running at All

If your furnace is not working, there are some steps you can take to troubleshoot before phoning a pro. 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 make sure power is reaching the furnace.

If there is power but your furnace won't blow hot air, the problem may lie with the ignition system or gas supply. In that case, it's better to consult a seasoned HVAC professional for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, that 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 cause inefficiency, increased energy consumption 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 exchanged on a regular basis 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, look at 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 Air-Right Energy Design. Prompt professional attention will help restore the proper functioning of your furnace and avoid further complications and high energy bills.

6. My Furnace Won't Stop Humming

Whenever your furnace is making a humming noise, it often is a sign of problems with the electrical elements or the blower motor. For this reason, 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 producing a consistent loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety risks.  One common problem that causes this is a malfunctioning blower motor or fan, which can create 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 best to consult with a heating and cooling specialist.

8. My Furnace Won't Start

If your furnace refuses to turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse that goes to the furnace is functioning properly. If these basic checks don't take care of 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 do the job, phone an expert for furnace repair.

9. My Furnace Is Not Igniting

Like a 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 the air filter and looking over your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting are a faulty igniter or nonfunctional 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 simply repaired by HVAC professionals like the team at Air-Right Energy Design.