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

Regardless of the problem, learning how your heating system works and a little bit about some typical furnace problems is essential 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 uncertain about the problem or lack the necessary skills and tools, it's best to call a reputable HVAC company like Farnell Heating & Air Conditioning Inc. 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 frequent heating dilemmas:

1. The Furnace Is Leaking

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water created during the combustion process is not completely draining away. This could be due to a blocked condensate drain line or a malfunctioning condensate pump. Another possible cause of water leakage from a furnace is a cracked heat exchanger, which can be responsible for water—as well as dangerous gases—coming out of the furnace.

It is imperative to correct water leaks promptly to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Farnell Heating & Air Conditioning Inc is recommended to diagnose and resolve the issue successfully.

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

Some potential causes for a furnace blowing cold air or not blowing hot air are a malfunctioning thermostat, a problem with the pilot light or ignition system, a clogged 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 better to contact a professional HVAC specialist to diagnose and fix the problem. They can give an accurate assessment and advise you on the proper solution.

3. My Furnace Is Not Keeping Up

A frequent reason your furnace isn’t keeping up on a cold day is that your home doesn’t have enough insulation, which can result in heat loss and decreased efficiency. Another reason your furnace is having difficulties is because it’s too small for your home, so it can’t produce enough heat to adequately warm the space. A broken thermostat or ductwork problems can also cause uneven heating.

To deal with this, first check your home’s insulation level and make sure it’s enough to protect your home. Also, look at the thermostat to make sure it’s set right and the batteries are working.

If the problem lingers, consider contacting an experienced HVAC company, such as Farnell Heating & Air Conditioning Inc, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying your thermostat settings.

4. My Furnace Isn't Running at All

If your furnace is not working, there are a few steps you can take to troubleshoot before phoning a professional. Check if the thermostat is set right and the batteries are fresh. 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 blow hot air, the problem may lie with the ignition system or gas supply. In that case, it's best to consult a seasoned HVAC technician for diagnosis and repair.

5. My Furnace Short Cycles

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

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be switched out regularly 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. Second, check 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 smart to call experts like the crew at Farnell Heating & Air Conditioning Inc. Prompt professional attention will help restore the proper functioning of your furnace and prevent more complications and high energy bills.

6. My Furnace Won't Stop Humming

If your furnace is making a humming noise, it often is a sign of problems with the electrical components or the blower motor. Therefore, if you detect your furnace making a humming noise, it is critical to take action.

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

7. My Furnace Is Making a Loud Noise

If your furnace is producing a consistent loud noise, it's important to address the issue quickly to prevent further damage or potential safety hazards.  One common reason 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.

Because of the complexity of furnace systems and potential risks involved, it's best to get a hold of 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 preferred temperature, is in heating mode and the batteries are good. Then, check if the circuit breaker or fuse controlling the furnace is working right. If these basic checks don't fix the problem, you can examine 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, call a professional for furnace repair.

9. My Furnace Won't Ignite

Like a a furnace that will not on at all, a furnace that isn’t igniting can be caused by a plugged 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 potential causes of a furnace not igniting are a faulty igniter or faulty flame sensor. Signs of these include the furnace continually making an attempt 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 easily fixed by HVAC professionals like the team at Farnell Heating & Air Conditioning Inc.