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

Regardless of the cause, knowing how your heating system works and a little bit about some typical furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional support. By watching 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 lack the necessary skills and tools, it's best to call a reputable HVAC company like Miller Climate Control LLC. We can accurately pinpoint 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. 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 completely draining away. This may be due to a clogged condensate drain line or a broken 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 correct water leaks quickly to prevent further damage to your furnace. Reaching out to a professional HVAC technician like the crew at Miller Climate Control LLC is recommended to diagnose and resolve the issue successfully.

2. My Furnace Makes 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 also may be your furnace is overheating and shutting off as a safety measure.

If your furnace won’t blow hot air, it's a good idea to contact a trained HVAC tech to diagnose and fix the problem. They can offer an accurate assessment and suggest the proper solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can lead to heat loss and lower efficiency. Another reason your furnace is falling short is because it’s not big enough for your home, so it can’t produce enough heat to effectively warm the space. A malfunctioning thermostat or ductwork problems can also produce inconsistent heating.

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

If the problem lingers, consider contacting an experienced HVAC company, such as Miller Climate Control LLC, 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 pro. Make sure the thermostat is set properly and the batteries are not dead. 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 no heat, the problem may lie with the ignition system or gas supply. In that case, it's a good idea to contact an experienced HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, this means it is turning on and off multiple times at short intervals instead of running in regular cycles like it ought to. This can cause inefficiency, higher energy bills and potential damage to your heating system.

If you suspect your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged on a regular basis 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, look at your thermostat and verify  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 Miller Climate Control LLC. 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

If 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 notice your furnace making a humming noise, it is crucial to take action.

If the noise doesn't go away, it is a good idea to  get in touch with a professional HVAC technician.

7. My Furnace Makes Loud Noises

If your furnace is producing a constant loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety concerns.  One common reason is a broken blower motor or fan, which can make a grinding or screeching sound. Another common cause is a loose or worn-out belt that may emit a squealing or rattling noise.

Because of the complexity of furnace systems and potential risks involved, it's best 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 preferred temperature, is in heating mode and the batteries are functioning. Then, see if the circuit breaker or fuse that controls the furnace is functioning properly. If these basic checks don't resolve the problem, you can check 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 a professional for furnace repair.

9. My Furnace Won't Ignite

Like a a furnace that will not on at all, a furnace that isn’t igniting can be the result of a plugged 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 common causes of a furnace not igniting could be a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace continually attempting to ignite without success, an absence of heat production or the furnace is making a burning or gas smell. Both of these issues can be simply addressed by HVAC pros like the team at Miller Climate Control LLC.