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

Regardless of the problem, knowing how your heating system works and a little bit about some typical furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional services. 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 an experienced HVAC company like Western Mechanical, Inc.. We can accurately diagnose 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 prevalent heating problems:

1. Your Furnace Leaks Water

A furnace can leak water for many 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 blocked condensate drain line or a malfunctioning 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—escaping from the furnace.

It is imperative to correct water leaks immediately to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Western Mechanical, Inc. is recommended to diagnose and resolve the issue effectively.

2. My Furnace Makes 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 could also be your furnace is overheating and shutting off as a safety precaution.

If your furnace won’t blow hot air, it's a good idea to contact a trained HVAC tech to diagnose and fix the problem. They can provide an accurate assessment and advise you on the appropriate solution.

3. My Furnace Can't Keep 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 not big enough for your home, so it can’t make enough heat to completely warm the space. A defective thermostat or ductwork problems can also result in 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 are working.

If the problem lingers, consider calling an experienced HVAC company, such as Western Mechanical, Inc., 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 couple of steps you can take to troubleshoot before phoning a heating specialist. Ensure the thermostat is set properly and the batteries are good. 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 your furnace won't ignite, the problem may be with the ignition system or gas supply. In that case, it's a good idea to reach out to a knowledgeable HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

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

If you believe your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be changed regularly 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. If that doesn’t do the trick, 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 staff at Western Mechanical, Inc.. Immediate professional attention will help restore the proper functioning of your furnace and reduce the chance of additional complications and high energy bills.

6. My Furnace Won't Stop Humming

When your furnace is making a humming noise, it often is an indication of problems with the electrical elements or the blower motor. For this reason, if you detect your furnace making a humming noise, it is crucial to take action.

If the noise doesn't go away, it is a good idea to  contact a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is emitting a persistent loud noise, it's important to handle the issue quickly to prevent further damage or potential safety concerns.  One common reason is a failing blower motor or fan, which can make a grinding or screeching sound. Another common 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 get a hold of 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 working. Then, see if the circuit breaker or fuse that goes to the furnace is working right. 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 get the job done, contact a professional for furnace repair.

9. My Furnace Is Not Igniting

Much like a furnace that won't turn on at all, a furnace that isn’t igniting can be the result of a clogged air filter or a tripped circuit breaker. So, checking out 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 malfunctioning flame sensor. Symptoms of these include the furnace continuously 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 addressed by HVAC professionals like the team at Western Mechanical, Inc..