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 affect your home at any moment.

Regardless of the cause, 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 services. By monitoring 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 unsure about the problem or aren't equipped with the necessary skills and tools, it's best to call a professional HVAC company like Bishop Heating & Air Conditioning. We can accurately diagnose the issue and perform 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. My Furnace Is Leaking 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 completely draining away. This might be due to a clogged condensate drain line or a broken 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—coming out of the furnace.

It is imperative to correct water leaks immediately to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Bishop Heating & Air Conditioning is recommended to diagnose and resolve the issue properly.

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

3. My Furnace Is Not Keeping 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 decreased efficiency. Another reason your furnace is having difficulties is because it’s too small for your home, so it can’t generate enough heat to effectively warm the space. A broken thermostat or ductwork problems can also result in uneven heating.

To address this, first check your home’s insulation level and make sure it’s enough to insulate your home. Also, check the thermostat to make sure it’s set right and the batteries still function.

If the problem continues, consider consulting with an experienced HVAC company, such as Bishop Heating & Air Conditioning, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or changing your thermostat settings.

4. My Furnace Won't Work

If your furnace is not working, there are a few steps you can take to troubleshoot before calling a heating specialist. 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 your furnace won't blow hot air, the problem may be with the ignition system or gas supply. In that case, it's better to consult a knowledgeable 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 rather than running in regular cycles like it should. 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 switched out regularly to ensure air flow, so if your furnace air filter is plugged with dirt you should exchange it for a clean one—and ensure it is pointing in the right direction. If that doesn’t do the trick, check 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 Bishop Heating & Air Conditioning. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of additional complications and high energy bills.

6. My Furnace Won't Stop Humming

If your furnace is making a humming noise, it often is an indication of a malfunction with the electrical hardware or the blower motor. Therefore, if you detect your furnace making a humming noise, it is critical to take action.

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

7. My Furnace Is Making a Loud Noise

If your furnace is emitting a consistent loud noise, it's important to deal with the issue right away to prevent further damage or potential safety risks.  One common cause of this is a broken 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.

Due to the complexity of furnace systems and potential risks involved, it's safer to contact 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 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 sending power to the unit. If these basic checks don't resolve the problem, you can examine 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, call an expert for furnace repair.

9. My Furnace Is on but Not Igniting

Much like 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, checking out the air filter and assessing 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 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 solved by HVAC professionals like the team at Bishop Heating & Air Conditioning.