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 cause, knowing 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 watching the furnace's behavior, listening for unusual 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 Walter's-Eaton's Electric, Plumbing, Heating & AC. 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 common 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 produced during the combustion process is not properly draining away. This could be due to a blocked condensate drain line or a broken 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—coming out of the furnace.

It is imperative to address water leaks promptly to prevent additional damage to your furnace. Reaching out to a professional HVAC technician like the crew at Walter's-Eaton's Electric, Plumbing, Heating & AC is recommended to diagnose and resolve the issue effectively.

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

Some likely 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 measure.

If your furnace does not blow hot air, it's better to contact a professional HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and suggest the correct 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 is lacking insulation, which can cause heat loss and reduced 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 cause insufficient heating.

To handle 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, look at the thermostat to make sure it’s set right and the batteries aren’t dead.

If the problem continues, consider calling an experienced HVAC company, such as Walter's-Eaton's Electric, Plumbing, Heating & AC, 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 Isn't Running at All

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a professional. 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 be with the ignition system or gas supply. In that case, it's best to consult a seasoned HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

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

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 dirty you should exchange it for a clean one—and make sure it is pointing in the right direction. If that doesn’t do the trick, 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 smart to call experts like the staff at Walter's-Eaton's Electric, Plumbing, Heating & AC. Immediate professional attention will help restore the proper functioning of your furnace and prevent further 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 a malfunction with the electrical parts or the blower motor. Therefore, if you detect your furnace making a humming noise, it is crucial to take action.

If the noise persists, it is a good idea to  employ a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is emitting a constant loud noise, it's important to address the issue right away to prevent further damage or potential safety hazards.  One common reason is a malfunctioning blower motor or fan, which can generate a grinding or screeching sound. Another potential cause is a loose or worn-out belt that may make a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's best 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 preferred temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse that goes to the furnace is sending power to the unit. If these basic checks don't fix the problem, you can examine 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 get the job done, call a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

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 assessing your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting are a faulty igniter or malfunctioning 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 simply fixed by HVAC pros like the team at Walter's-Eaton's Electric, Plumbing, Heating & AC.