Whether it’s a leaky furnace or if you flip the switch to power up 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, understanding how your heating system works and a little bit about some typical furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional services. By observing 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 don't have the necessary skills and tools, it's best to call an experienced HVAC company like Brandywine Heating & Air. We can accurately pinpoint the issue and complete 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 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 created during the combustion process is not completely draining away. This might be due to a clogged condensate drain line or a failing 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—escaping from the furnace.

It is important to deal with water leaks quickly to prevent additional damage to your furnace. Consulting with a professional HVAC technician like the crew at Brandywine Heating & Air is recommended to diagnose and resolve the issue successfully.

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

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

If your furnace will not blow hot air, it's a good idea to contact a trained HVAC technician to diagnose and fix the problem. They can provide an accurate assessment and recommend the appropriate solution.

3. My Furnace Struggles to Keep Up

A widespread reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can cause heat loss and decreased efficiency. Another reason your furnace is having difficulties is because it’s not powerful enough for your home, so it can’t produce enough heat to completely warm the space. A broken thermostat or ductwork problems can also produce inconsistent 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, check the thermostat to ensure it’s set right and the batteries still function.

If the problem continues, consider calling an experienced HVAC company, such as Brandywine Heating & Air, 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 some steps you can take to troubleshoot before calling a pro. Ensure the thermostat is set properly and the batteries are not dead. 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 reach out to an experienced HVAC technician for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, it means it is turning on and off often 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 heating system.

If you believe your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be changed regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and ensure it is pointing in the right direction. Second, 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 smart to call experts like the crew at Brandywine Heating & Air. Quick professional attention will help restore the proper functioning of your furnace and avoid more complications and high energy bills.

6. My Furnace Hums All the Time

Whenever your furnace is making a humming noise, it often is a sign of a malfunction with the electrical components or the blower motor. Because of this, if you detect your furnace making a humming noise, it is crucial to take action.

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

7. My Furnace Makes Loud Noises

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

Due to the complexity of furnace systems and potential risks involved, it's safer to get a hold of a heating and cooling specialist.

8. My Furnace Won't Start

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 good. Then, see if the circuit breaker or fuse that goes to the furnace is sending power to the unit. If these basic checks don't take care of the problem, you can examine 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 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 caused by a plugged air filter or a tripped circuit breaker. So, inspecting 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 nonfunctional flame sensor. Symptoms of these include the furnace repeatedly making an attempt 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 repaired by HVAC pros like the team at Brandywine Heating & Air.