Solved: Furnace 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 problem, learning how your heating system works and a little bit about some frequent furnace problems is vital in deciding whether you can troubleshoot on your own or if you need professional support. By noting 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 don't have the necessary skills and tools, it's best to call a professional HVAC company like JTech Mechanical. We can accurately pinpoint 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 common heating dilemmas:

1. Your Furnace Leaks Water

A furnace can leak water for many 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 blocked condensate drain line or a malfunctioning condensate pump. Another likely cause of water leakage from a furnace is a cracked heat exchanger, which can lead to water—as well as dangerous gases—leaking out of the furnace.

It is important to deal with water leaks immediately to prevent further damage to your furnace. Reaching out to a professional HVAC technician like the crew at JTech Mechanical is recommended to diagnose and resolve the issue successfully.

2. My Furnace Is Blowing Cold Air/Lack of Heat

Some possible causes for a furnace blowing cold air or not blowing hot air include 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 best to contact a skilled HVAC specialist to diagnose and fix the problem. They can offer an accurate assessment and recommend the appropriate solution.

3. My Furnace Can't Keep Up

A widespread reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can cause heat loss and decreased 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 completely warm the space. A malfunctioning thermostat or ductwork problems can also cause inconsistent heating.

To correct 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 ensure it’s set right and the batteries still function.

If the problem lingers, consider calling an experienced HVAC company, such as JTech Mechanical, who can assess your system, determine the root cause and provide solutions such as furnace replacement, repairing ductwork or adjusting your thermostat settings.

4. My Furnace Isn't Running at All

If your furnace is not working, there are a couple of steps you can take to troubleshoot before calling a pro. Make sure the thermostat is set correctly and the batteries are fresh. If the furnace still doesn't turn on, check the circuit breaker or fuse box to ensure power is reaching the unit.

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 contact a seasoned HVAC technician for diagnosis and repair.

5. My Furnace Short Cycles

If your furnace is short cycling, this means it is turning on and off frequently at short intervals instead of running in regular cycles like it ought to. 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 check your unit’s air filter. Filters should be changed when they are dirty 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. If that doesn’t do the trick, 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 crew at JTech Mechanical. Prompt 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

When your furnace is making a humming noise, it often is a sign of problems 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 continues, it is better that you  contact a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is making a persistent 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 broken 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.

Due to the complexity of furnace systems and potential risks involved, it's safer to get in touch with a heating and cooling specialist.

8. My Furnace Can't Turn On

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 good. Then, check if the circuit breaker or fuse that goes to the furnace is working right. If these basic checks don't address the problem, you can examine 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 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 plugged air filter or a tripped circuit breaker. So, examining 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 are a faulty igniter or faulty flame sensor. Signs 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 professionals like the team at JTech Mechanical.