Solved: Furnace Is Leaking Water and 8 Other Furnace Problems

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 affect your home at any moment.

Regardless of the cause, 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 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 aren't equipped with the necessary skills and tools, it's best to call an experienced HVAC company like Central Air LLC. We can accurately identify the issue and complete the required repairs or maintenance, so we can get your furnace working again ASAP.

Here's more about what causes a furnace to leak water and eight other frequent heating dilemmas:

1. The Furnace Is Leaking

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 properly draining away. This might be due to a plugged condensate drain line or a broken condensate pump. Another possible cause of water leakage from a furnace is a cracked heat exchanger, which can be responsible for water—as well as dangerous gases—leaking out of the furnace.

It is imperative to manage water leaks immediately to prevent additional damage to your furnace. Contacting a professional HVAC technician like the crew at Central Air LLC 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 blocked 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 tech 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 frequent reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can cause heat loss and lower efficiency. Another reason your furnace is struggling is because it’s too small for your home, so it can’t produce enough heat to adequately warm the space. A broken thermostat or ductwork problems can also result in inconsistent heating.

To deal with this, first look at your home’s insulation level and make sure it’s enough to protect your home. Also, look at the thermostat to see if it’s set right and the batteries aren’t dead.

If the problem continues, consider calling an experienced HVAC company, such as Central Air LLC, 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 Isn't Running at All

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a professional. 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 verify power is reaching the furnace.

If there is power but your furnace won't ignite, the problem may be with the ignition system or gas supply. In that case, it's better to reach out to a seasoned HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, that means it is turning on and off multiple times at short intervals as opposed to running in regular cycles like it should. This can lead to inefficiency, increased energy consumption and potential damage to your unit.

If you think your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be switched out regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and make sure it is pointing in the right direction. Next, go to your thermostat and verify  it’s set right and the batteries are good.

If those two things don’t work, it’s best to call experts like the crew at Central Air LLC. Immediate professional attention will help restore the proper functioning of your furnace and prevent further complications and high energy bills.

6. My Furnace Hums All the Time

If your furnace is making a humming noise, it often is an indication of an issue with the electrical components or the blower motor. Because of this, if you detect your furnace making a humming noise, it is important to take action.

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

7. My Furnace Is Noisy

If your furnace is making a constant loud noise, it's important to deal with the issue promptly to prevent further damage or potential safety risks.  One common reason is a malfunctioning blower motor or fan, which can create a grinding or screeching sound. Another possible cause is a loose or worn-out belt that may produce 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 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 good. Then, check if the circuit breaker or fuse that goes to the furnace is working right. If these basic checks don't fix 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 get the job done, contact a professional for furnace repair.

9. My Furnace Is Not Igniting

Similar to a furnace not turning on at all, a furnace that isn’t igniting can be caused by a dirty air filter or a tripped circuit breaker. So, examining the air filter and assessing your circuit breakers are a good place to start.

Other common causes of a furnace not igniting are a faulty igniter or malfunctioning flame sensor. Signs of these include the furnace continuously attempting to ignite without success, no 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 Central Air LLC.