Whether it’s a leaky furnace or if you flip the switch to start your heating system in the fall and it won’t start, common furnace problems can affect your home at any moment.

Regardless of the issue, learning 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 noting 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 not sure about the problem or aren't equipped with the necessary skills and tools, it's best to call a professional HVAC company like Van Haaften Plumbing & Heating. 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 frequent heating problems:

1. The Furnace Is Leaking

A furnace can leak water for several reasons. One possibility is a condensate leak, where the water produced during the combustion process is not effectively draining away. This may be due to a blocked condensate drain line or a malfunctioning condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can lead to water—as well as dangerous gases—escaping from the furnace.

It is imperative to manage water leaks immediately to prevent more damage to your furnace. Reaching out to a professional HVAC technician like the crew at Van Haaften Plumbing & Heating is recommended to diagnose and resolve the issue effectively.

2. My Furnace Makes Cold Air/Lack of Heat

Some possible causes for a furnace blowing cold air or not blowing hot air could be a malfunctioning thermostat, a problem with the pilot light or ignition system, a clogged air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety precaution.

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 correct solution.

3. My Furnace Is Not Keeping 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 lower efficiency. Another reason your furnace is falling short is because it’s too small for your home, so it can’t produce enough heat to completely warm the space. A defective 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 keep warm air in and cold air out of your home. Also, look at the thermostat to ensure it’s set right and the batteries are working.

If the problem continues, consider calling an experienced HVAC company, such as Van Haaften Plumbing & Heating, 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 a few steps you can take to troubleshoot before calling a heating specialist. 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 verify power is reaching the unit.

If there is power but your furnace won't blow hot air, the problem may lie with the ignition system or gas supply. In that case, it's best to reach out to an experienced HVAC technician for diagnosis and repair.

5. My Furnace Is Short Cycling

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 cause inefficiency, increased energy consumption and potential damage to your unit.

If you believe your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be exchanged regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and be sure it is pointing in the right direction. Next, look at 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 team at Van Haaften Plumbing & Heating. Prompt professional attention will help restore the proper functioning of your furnace and reduce the chance of further complications and high energy bills.

6. My Furnace Hums All the Time

Whenever your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical hardware or the blower motor. Because of this, if you hear 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 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 failing blower motor or fan, which can generate a grinding or screeching sound. Another possible cause is a loose or worn-out belt that may make a squealing or rattling noise.

Given the complexity of furnace systems and potential risks involved, it's best to get in touch 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 right temperature, is in heating mode and the batteries are working. Then, see if the circuit breaker or fuse that controls the furnace is functioning properly. If these basic checks don't fix the problem, you can inspect 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 work, call a heating specialist for furnace repair.

9. My Furnace Won't Ignite

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 taking a peek at your circuit breakers are a good place to start.

Other likely causes of a furnace not igniting include a faulty igniter or nonfunctional flame sensor. Indications of these include the furnace continuously trying to ignite without success, no heat production or the furnace is making a burning or gas smell. Both of these issues can be easily fixed by HVAC pros like the team at Van Haaften Plumbing & Heating.