Whether it’s a leaky furnace or if you flick the switch to power up 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 cause, 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 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 not sure about the problem or lack the necessary skills and tools, it's best to call an experienced HVAC company like The Frazier Company. We can accurately pinpoint the issue and perform 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 frequent heating dilemmas:

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 completely draining away. This may be due to a plugged condensate drain line or a failing 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—coming out of the furnace.

It is necessary to address water leaks quickly to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at The Frazier Company 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 include a malfunctioning thermostat, a problem with the pilot light or ignition system, a clogged air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety measure.

If your furnace does not blow hot air, it's best to contact a professional HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and suggest the correct solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can cause heat loss and lower efficiency. Another reason your furnace is having difficulties is because it’s too small for your home, so it can’t make enough heat to completely warm the space. A broken thermostat or ductwork problems can also produce inconsistent 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 ensure it’s set right and the batteries are working.

If the problem won’t go away, consider contacting an experienced HVAC company, such as The Frazier Company, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying 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. Ensure the thermostat is set properly 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 system.

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

5. My Furnace Is Short Cycling

If your furnace is short cycling, that means it is turning on and off multiple times at short intervals as opposed to running in regular cycles like it should. This can cause inefficiency, higher energy bills and potential damage to your furnace.

If you think your furnace is short cycling, the first step is to check 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, go to your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s best to call experts like the staff at The Frazier Company. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of further 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 problems with the electrical components or the blower motor. Because of this, if you detect your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is best to  contact a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

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

Given the complexity of furnace systems and potential risks involved, it's best to contact a heating and cooling specialist.

8. My Furnace Can't Turn On

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, check if 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, phone a heating specialist for furnace repair.

9. My Furnace Won't Ignite

Similar to a furnace not turning 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 taking a peek at your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting include a faulty igniter or faulty flame sensor. Signs of these include the furnace repeatedly trying to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be simply fixed by HVAC specialists like the team at The Frazier Company.