Whether it’s a leaky furnace or if you flip the switch to turn on 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, understanding 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 assistance. By noting the furnace's behavior, listening for peculiar noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're uncertain about the problem or aren't equipped with the necessary skills and tools, it's best to call an experienced HVAC company like Pure Comfort Heating and Air Conditioning. We can accurately identify the issue and complete 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 dilemmas:

1. My Furnace Is Leaking Water

A furnace can leak water for many reasons. One possibility is a condensate leak, where the water created during the combustion process is not properly draining away. This may be due to a blocked condensate drain line or a broken 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—escaping from the furnace.

It is necessary to deal with water leaks quickly to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Pure Comfort Heating and Air Conditioning is recommended to diagnose and resolve the issue successfully.

2. My Furnace Is Blowing Cold Air/Lack of Heat

Some possible 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 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 provide an accurate assessment and suggest the correct solution.

3. My Furnace Can't Keep Up

A widespread reason your furnace isn’t keeping up on a cold day is that your home lacks 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 completely warm the space. A malfunctioning thermostat or ductwork problems can also produce inconsistent heating.

To correct this, first assess your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of your home. Also, examine the thermostat to see if it’s set right and the batteries aren’t dead.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Pure Comfort Heating and Air Conditioning, who can look over your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying 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 pro. Make sure the thermostat is set right and the batteries are fresh. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the unit.

If there is power but your furnace won't ignite, the problem may lie with the ignition system or gas supply. In that case, it's better to contact an experienced HVAC professional for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, this means it is turning on and off frequently at short intervals as opposed to running in regular cycles like it ought to. This can lead to inefficiency, more energy use and potential damage to your unit.

If you believe your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged 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. Next, 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 team at Pure Comfort Heating and Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and avoid more complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is an indication of a malfunction with the electrical parts or the blower motor. Because of this, 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 Noisy

If your furnace is producing a consistent loud noise, it's important to handle the issue right away to prevent further damage or potential safety hazards.  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.

Because of the complexity of furnace systems and potential risks involved, it's better to consult with a heating and cooling specialist.

8. My Furnace Can't Turn On

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 good. Then, see if the circuit breaker or fuse controlling the furnace is working right. If these basic checks don't resolve the problem, you can check 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 do the job, phone an expert for furnace repair.

9. My Furnace Is Not Igniting

Like a a furnace not turning 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 potential causes of a furnace not igniting include a faulty igniter or faulty flame sensor. Indications of these include the furnace continually 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 repaired by HVAC pros like the team at Pure Comfort Heating and Air Conditioning.