Solved: Furnace Is Leaking Water and 8 Other Furnace Problems

Whether it’s a leaky furnace or if you flip the switch to start 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 issue, understanding 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 assistance. 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 unsure about the problem or lack the necessary skills and tools, it's best to call a professional HVAC company like Scott Temperature. We can accurately pinpoint the issue and execute 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 frequent 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 produced during the combustion process is not effectively draining away. This may be due to a clogged condensate drain line or a broken condensate pump. Another possible 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 necessary to deal with water leaks immediately to prevent more damage to your furnace. Consulting with a professional HVAC technician like the crew at Scott Temperature is recommended to diagnose and resolve the issue effectively.

2. My Furnace Makes Cold Air/Lack of Heat

Some likely 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 is also possible your furnace is overheating and shutting off as a safety measure.

If your furnace will not blow hot air, it's better to contact a trained HVAC tech to diagnose and fix the problem. They can provide an accurate assessment and advise you on the appropriate 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 doesn’t have enough insulation, which can lead to heat loss and lower efficiency. Another reason your furnace is struggling is because it’s not big enough for your home, so it can’t generate enough heat to effectively warm the space. A malfunctioning thermostat or ductwork problems can also produce inconsistent heating.

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

If the problem continues, consider contacting an experienced HVAC company, such as Scott Temperature, who can inspect your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or modifying 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 phoning a professional. Check if the thermostat is set right and the batteries are good. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the system.

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

5. My Furnace Short Cycles

If your furnace is short cycling, that means it is turning on and off often at short intervals instead of running in regular cycles like it is designed to do. This can result in inefficiency, higher energy bills and potential damage to your furnace.

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged on a regular basis to ensure air flow, so if your furnace air filter is dirty 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 Scott Temperature. Immediate professional attention will help restore the proper functioning of your furnace and avoid further complications and high energy bills.

6. My Furnace Is Making a Humming Noise

Whenever your furnace is making a humming noise, it often is a symptom of an issue with the electrical elements or the blower motor. For this reason, if you hear your furnace making a humming noise, it is important to take action.

If the noise persists, it is a good idea to  get in touch with a professional HVAC technician.

7. My Furnace Is Making a Loud Noise

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

Given the complexity of furnace systems and potential risks involved, it's best to consult with a heating and cooling specialist.

8. My Furnace Won't Start

If your furnace will not turn on, make sure the thermostat is set to the right temperature, is in heating mode and the batteries are good. Then, verify that the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't address the problem, you can inspect 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 work, call a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

Similar to a furnace that will not 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 taking a peek at your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting could be a faulty igniter or nonfunctional flame sensor. Symptoms of these include the furnace continually making an attempt 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 very easily fixed by HVAC pros like the team at Scott Temperature.