Whether it’s a leaky furnace or if you throw the switch to power up 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, 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 assistance. By observing 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 not sure about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like Alpine Summit Heating & Cooling. We can accurately identify 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 prevalent heating dilemmas:

1. Your Furnace Leaks 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 effectively draining away. This could be due to a plugged condensate drain line or a malfunctioning condensate pump. Another likely 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 imperative to correct water leaks quickly to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Alpine Summit Heating & Cooling 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 plugged air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety precaution.

If your furnace does not blow hot air, it's best to contact a professional HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend the proper solution.

3. My Furnace Can't Keep 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 reduced efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t make enough heat to effectively warm the space. A defective thermostat or ductwork problems can also produce uneven heating.

To deal with this, first check 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 make sure it’s set right and the batteries are working.

If the problem lingers, consider contacting an experienced HVAC company, such as Alpine Summit Heating & Cooling, who can inspect 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 phoning a professional. Check if the thermostat is set correctly and the batteries are fresh. If the furnace still doesn't power on, check the circuit breaker or fuse box to verify power is reaching the furnace.

If there is power but no heat, the problem may rest with the ignition system or gas supply. In that case, it's better to contact an experienced HVAC technician for diagnosis and repair.

5. My Furnace Turns On and Off

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 is designed to do. This can result in inefficiency, higher energy bills 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 exchanged when they are dirty 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, go to 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 staff at Alpine Summit Heating & Cooling. Immediate 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 Won't Stop Humming

When your furnace is making a humming noise, it often is an indication of problems with the electrical parts or the blower motor. For this reason, if you detect your furnace making a humming noise, it is important to take action.

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

7. My Furnace Makes Loud Noises

If your furnace is making a consistent loud noise, it's important to deal with the issue right away to prevent further damage or potential safety concerns.  One common problem that causes this is a broken 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.

Due to the complexity of furnace systems and potential risks involved, it's safer to consult with 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 desired temperature, is in heating mode and the batteries are working. Then, check if the circuit breaker or fuse that goes to the furnace is functioning properly. If these basic checks don't fix 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, contact a heating specialist for furnace repair.

9. My Furnace Is on but Not Igniting

Similar to a furnace that won't turn on at all, a furnace that isn’t igniting can be caused by a dirty air filter or a tripped circuit breaker. So, inspecting the air filter and taking a peek at your circuit breakers are a good place to start.

Other common causes of a furnace not igniting include a faulty igniter or malfunctioning flame sensor. Symptoms of these include the furnace continuously attempting to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be easily solved by HVAC specialists like the team at Alpine Summit Heating & Cooling.