Whether it’s a leaky furnace or if you flip the switch to start 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 typical furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional support. 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 don't have the necessary skills and tools, it's best to call an experienced HVAC company like Northglenn Heating & Air Conditioning. We can accurately identify the issue and complete 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 prevalent 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 properly draining away. This may be due to a blocked condensate drain line or a failing 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 important to manage water leaks immediately to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Northglenn Heating & Air Conditioning is recommended to diagnose and resolve the issue effectively.

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

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

If your furnace does not blow hot air, it's better to contact a trained HVAC specialist to diagnose and fix the problem. They can give an accurate assessment and suggest the appropriate 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 is lacking insulation, which can result in heat loss and decreased efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t produce enough heat to adequately warm the space. A malfunctioning thermostat or ductwork problems can also cause uneven heating.

To correct this, first look at 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 continues, consider contacting an experienced HVAC company, such as Northglenn Heating & 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 Is Not Working

If your furnace is not working, there are a few steps you can take to troubleshoot before contacting a heating specialist. Ensure the thermostat is set correctly and the batteries are good. 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 your furnace won't ignite, the problem may lie with the ignition system or gas supply. In that case, it's a good idea to contact a seasoned HVAC technician 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 ought to. This can result in inefficiency, increased energy consumption 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 switched out regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and make sure 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 best to call experts like the crew at Northglenn Heating & Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of 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 a symptom of an issue with the electrical hardware or the blower motor. Therefore, if you hear your furnace making a humming noise, it is crucial to take action.

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

7. My Furnace Is Making a Loud Noise

If your furnace is making a consistent loud noise, it's important to address the issue right away to prevent further damage or potential safety risks.  One common problem that causes 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 produce a squealing or rattling noise.

Due to 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 refuses to turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are good. Then, check if the circuit breaker or fuse controlling the furnace is sending power to the unit. If these basic checks don't resolve 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 do the job, call a professional 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 caused by a dirty 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 are a faulty igniter or faulty flame sensor. Symptoms of these include the furnace repeatedly 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 very easily solved by HVAC professionals like the team at Northglenn Heating & Air Conditioning.