Whether it’s a leaky furnace or if you throw the switch to turn on 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 problem, understanding 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 support. By observing 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 unsure about the problem or aren't equipped with the necessary skills and tools, it's best to call a reputable HVAC company like A2Z Air Inc. We can accurately pinpoint the issue and execute the required repairs or maintenance, so we can get your furnace working again ASAP.

Here's more about what causes a furnace to leak water and eight other frequent heating dilemmas:

1. My Furnace Is Leaking Water

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water created during the combustion process is not effectively draining away. This might be due to a blocked condensate drain line or a failing condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—leaking out of the furnace.

It is important to manage water leaks quickly to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at A2Z Air 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 could also be your furnace is overheating and shutting off as a safety mechanism.

If your furnace does not blow hot air, it's best to contact a skilled HVAC tech 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 widespread 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 lower efficiency. Another reason your furnace is having difficulties is because it’s not powerful enough for your home, so it can’t make enough heat to completely warm the space. A broken thermostat or ductwork problems can also produce uneven heating.

To handle this, first look at your home’s insulation level and make sure it’s enough to insulate your home. Also, look at the thermostat to make sure it’s set right and the batteries still function.

If the problem won’t go away, consider contacting an experienced HVAC company, such as A2Z Air Inc, 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 phoning a professional. Check if the thermostat is set correctly and the batteries are fresh. If the furnace still doesn't turn 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 be with the ignition system or gas supply. In that case, it's best to reach out to a seasoned HVAC professional for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, that means it is turning on and off multiple times at short intervals instead of running in regular cycles like it should. This can cause inefficiency, more energy use and potential damage to your unit.

If you suspect your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be changed on a regular basis to ensure air flow, so if your furnace air filter is plugged with dirt you should exchange it for a clean one—and ensure it is pointing in the right direction. Next, look at 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 a good idea to call experts like the crew at A2Z Air Inc. Prompt 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

Whenever your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical parts or the blower motor. Because of this, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise continues, it is better that you  contact a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is emitting a persistent loud noise, it's important to deal with the issue promptly to prevent further damage or potential safety concerns.  One common cause of this is a malfunctioning blower motor or fan, which can create a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may produce a squealing or rattling noise.

Given the complexity of furnace systems and potential risks involved, it's better 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 preferred temperature, is in heating mode and the batteries are functioning. Then, see 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 check 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 work, call a professional for furnace repair.

9. My Furnace Won't Ignite

Much like a furnace that won't turn 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 could be a faulty igniter or nonfunctional flame sensor. Symptoms of these include the furnace continually 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 addressed by HVAC specialists like the team at A2Z Air Inc.