Whether it’s a leaky furnace or if you flick the switch to start your heating system in the fall and it won’t start, common furnace problems can impact 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 assistance. By monitoring 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 not sure about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like Wallpe Heating & Cooling. We can accurately pinpoint 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 frequent heating problems:

1. My Furnace Is Leaking 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 effectively draining away. This might be due to a clogged condensate drain line or a failing 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—coming out of the furnace.

It is necessary to manage water leaks quickly to prevent further damage to your furnace. Contacting a professional HVAC technician like the crew at Wallpe Heating & Cooling is recommended to diagnose and resolve the issue properly.

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

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 blocked air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety precaution.

If your furnace won’t blow hot air, it's better to contact a skilled HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and advise you on the proper 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 is lacking insulation, which can result in heat loss and reduced efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t generate enough heat to adequately warm the space. A defective thermostat or ductwork problems can also cause insufficient heating.

To correct this, first look at your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of your home. Also, look at the thermostat to make sure it’s set right and the batteries are working.

If the problem won’t go away, consider calling an experienced HVAC company, such as Wallpe Heating & Cooling, who can look over 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 calling a pro. Make sure the thermostat is set right and the batteries are not dead. If the furnace still doesn't start, check the circuit breaker or fuse box to ensure power is reaching the furnace.

If there is power but your furnace won't ignite, the problem may rest with the ignition system or gas supply. In that case, it's better to consult a knowledgeable HVAC professional 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 is designed to do. This can cause inefficiency, higher energy bills and potential damage to your heating system.

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 dirty you should exchange it for a clean one—and ensure it is pointing in the right direction. Next, look at your thermostat and verify  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 staff at Wallpe Heating & Cooling. Immediate professional attention will help restore the proper functioning of your furnace and avoid further complications and high energy bills.

6. My Furnace Is Making a Humming Noise

When your furnace is making a humming noise, it often is an indication of problems with the electrical components or the blower motor. Therefore, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise doesn't go away, it is best to  get in touch with a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is producing a persistent loud noise, it's important to handle the issue promptly to prevent further damage or potential safety risks.  One common problem that causes this is a broken blower motor or fan, which can make 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 Is Not Turning On

If your furnace will not 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 controls the furnace is functioning properly. If these basic checks don't fix the problem, you can inspect the furnace's power switch or emergency shutoff switch to ensure 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 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 plugged air filter or a tripped circuit breaker. So, examining the air filter and looking over your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting could be a faulty igniter or malfunctioning flame sensor. Symptoms 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 very easily fixed by HVAC specialists like the team at Wallpe Heating & Cooling.