Whether it’s a leaky furnace or if you throw the switch to start 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, knowing how your heating system works and a little bit about some common furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional support. By watching 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 don't have the necessary skills and tools, it's best to call an experienced HVAC company like Pratt Brothers. We can accurately pinpoint the issue and execute 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 might be due to a blocked condensate drain line or a malfunctioning condensate pump. Another likely cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—coming out of the furnace.

It is important to correct water leaks immediately to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Pratt Brothers is recommended to diagnose and resolve the issue successfully.

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

Some potential causes for a furnace blowing cold air or not blowing hot air include a malfunctioning thermostat, a problem with the pilot light or ignition system, a blocked 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 won’t blow hot air, it's a good idea to contact a professional HVAC technician to diagnose and fix the problem. They can give an accurate assessment and recommend the appropriate solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can result in heat loss and reduced 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 effectively warm the space. A defective thermostat or ductwork problems can also produce inconsistent heating.

To handle this, first check your home’s insulation level and make sure it’s enough to protect your home. Also, check the thermostat to make sure it’s set right and the batteries are working.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Pratt Brothers, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting your thermostat settings.

4. My Furnace Isn't Running at All

If your furnace is not working, there are a few steps you can take to troubleshoot before contacting a professional. Check if the thermostat is set right and the batteries are good. If the furnace still doesn't power 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 rest 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 Turns On and Off

If your furnace is short cycling, it means it is turning on and off multiple times at short intervals rather than running in regular cycles like it should. This can result in inefficiency, higher energy bills and potential damage to your furnace.

If you believe your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged 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 be sure it is pointing in the right direction. If that doesn’t do the trick, go to 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 staff at Pratt Brothers. 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

If your furnace is making a humming noise, it often is an indication of an issue with the electrical parts or the blower motor. For this reason, if you notice your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is best to  get in touch with a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a consistent loud noise, it's important to deal with the issue promptly to prevent further damage or potential safety hazards.  One common problem that causes this is a failing blower motor or fan, which can make 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 safer to contact a heating and cooling specialist.

8. My Furnace Can't Turn On

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

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

9. My Furnace Won't Ignite

Like a a furnace that will not 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 taking a peek at your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting could be a faulty igniter or faulty flame sensor. Symptoms of these include the furnace continuously attempting 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 easily addressed by HVAC professionals like the team at Pratt Brothers.