Whether it’s a leaky furnace or if you throw the switch to power up your heating system when the weather gets cold and it won’t start, common furnace problems can affect 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 services. By monitoring 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 aren't equipped with the necessary skills and tools, it's best to call a professional HVAC company like Refrigeration Systems Ltd.. 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 properly draining away. This could 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 lead to water—as well as dangerous gases—coming out of the furnace.

It is important to address water leaks quickly to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at Refrigeration Systems Ltd. is recommended to diagnose and resolve the issue successfully.

2. My Furnace Blows Cold Air/Lack of Heat

Some likely causes for a furnace blowing cold air or not blowing hot air could be a malfunctioning thermostat, a problem with the pilot light or ignition system, a plugged air filter, or a malfunctioning heating element. It could also be your furnace is overheating and shutting off as a safety measure.

If your furnace won’t blow hot air, it's best to contact a professional HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and suggest the correct solution.

3. My Furnace Struggles to Keep Up

A frequent reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can cause heat loss and reduced 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 defective thermostat or ductwork problems can also cause uneven heating.

To deal with this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, check the thermostat to ensure it’s set right and the batteries aren’t dead.

If the problem lingers, consider calling an experienced HVAC company, such as Refrigeration Systems Ltd., 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 Isn't Running at All

If your furnace is not working, there are a couple of steps you can take to troubleshoot before contacting a heating specialist. Check if the thermostat is set correctly and the batteries are good. If the furnace still doesn't power on, check the circuit breaker or fuse box to verify power is reaching the system.

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 contact an experienced 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 rather than running in regular cycles like it should. This can cause inefficiency, more energy use and potential damage to your heating system.

If you think your furnace is short cycling, the first step is to pull out 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 be sure it is pointing in the right direction. Second, check your thermostat and make sure  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 crew at Refrigeration Systems Ltd.. Quick professional attention will help restore the proper functioning of your furnace and reduce the chance of more complications and high energy bills.

6. My Furnace Hums All the Time

When your furnace is making a humming noise, it often is a sign of an issue with the electrical components or the blower motor. Therefore, if you hear your furnace making a humming noise, it is important to take action.

If the noise doesn't go away, it is best to  employ a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

If your furnace is making a persistent loud noise, it's important to address the issue right away to prevent further damage or potential safety risks.  One common cause of this is a broken blower motor or fan, which can create a grinding or screeching sound. Another common cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Given 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 Can't Turn On

If your furnace won't turn on, make sure the thermostat is set to the right temperature, is in heating mode and the batteries are good. Then, check if the circuit breaker or fuse that goes to the furnace is working right. If these basic checks don't address the problem, you can inspect the furnace's power switch or emergency shutoff switch to make sure they're in the "on" position and weren’t accidentally turned off.

If those steps don’t work, phone a professional for furnace repair.

9. My Furnace Is on but Not Igniting

Similar to a furnace not turning on at all, a furnace that isn’t igniting can be caused by a plugged 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 potential causes of a furnace not igniting could be a faulty igniter or faulty flame sensor. Indications of these include the furnace continuously attempting 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 addressed by HVAC professionals like the team at Refrigeration Systems Ltd..