Whether it’s a leaky furnace or if you flick the switch to turn on your heating system when it gets chilly 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 vital in deciding whether you can troubleshoot on your own or if you need professional services. By watching 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 not sure about the problem or aren't equipped with the necessary skills and tools, it's best to call an experienced HVAC company like Woody's Sudden Service. We can accurately diagnose the issue and perform 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 issues:

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 created during the combustion process is not properly draining away. This may be due to a clogged 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—leaking out of the furnace.

It is important to address water leaks immediately to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Woody's Sudden Service is recommended to diagnose and resolve the issue properly.

2. My Furnace Blows Cold Air/Lack of Heat

Some likely 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 better to contact a trained HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and recommend the appropriate 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 doesn’t have enough insulation, which can cause heat loss and decreased efficiency. Another reason your furnace is struggling is because it’s not powerful enough for your home, so it can’t produce enough heat to effectively warm the space. A broken thermostat or ductwork problems can also cause inconsistent heating.

To deal with this, first assess your home’s insulation level and make sure it’s enough to protect your home. Also, check the thermostat to see if it’s set right and the batteries still function.

If the problem won’t go away, consider contacting an experienced HVAC company, such as Woody's Sudden Service, who can look over your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or changing 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 phoning a heating specialist. Ensure the thermostat is set properly and the batteries are good. If the furnace still doesn't start, check the circuit breaker or fuse box to verify power is reaching the system.

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

5. My Furnace Short Cycles

If your furnace is short cycling, that means it is turning on and off frequently at short intervals as opposed to 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 believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be switched out when they are dirty 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. 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 Woody's Sudden Service. Quick professional attention will help restore the proper functioning of your furnace and avoid 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 an issue with the electrical parts or the blower motor. Because of this, if you detect your furnace making a humming noise, it is important to take action.

If the noise doesn't go away, it is best to  contact a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a constant loud noise, it's important to address the issue quickly to prevent further damage or potential safety risks.  One common problem that causes this is a malfunctioning 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.

Because of the complexity of furnace systems and potential risks involved, it's better to get in touch with 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 preferred temperature, is in heating mode and the batteries are working. Then, verify that the circuit breaker or fuse controlling the furnace is functioning properly. 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, phone an expert for furnace repair.

9. My Furnace Is on but Not Igniting

Similar to 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 the air filter and looking over your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting could be a faulty igniter or malfunctioning flame sensor. Signs 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 specialists like the team at Woody's Sudden Service.