Solved: Furnace Is Leaking Water and 8 Other Heating Problems

Whether it’s a leaky furnace or if you throw the switch to start your heating system when the weather gets cold and it won’t start, common furnace problems can impact your home at any moment.

Regardless of the issue, knowing how your heating system works and a little bit about some frequent furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional services. 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 uncertain about the problem or don't have the necessary skills and tools, it's best to call a reputable HVAC company like JTech Mechanical. We can accurately diagnose the issue and perform 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 issues:

1. The Furnace Is Leaking

A furnace can leak water for a number of reasons. One possibility is a condensate leak, where the water released during the combustion process is not properly draining away. This could be due to a clogged condensate drain line or a failing condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can be responsible for water—as well as dangerous gases—coming out of the furnace.

It is important to manage water leaks immediately to prevent more 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 properly.

2. My Furnace Blows Cold Air/Not Blowing Hot Air

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 plugged air filter, or a malfunctioning heating element. It also may be your furnace is overheating and shutting off as a safety mechanism.

If your furnace does not blow hot air, it's better to contact a skilled HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and advise you on the correct solution.

3. My Furnace Struggles to Keep Up

A frequent reason your furnace isn’t keeping up on a cold day is that your home is lacking insulation, which can cause 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 generate enough heat to completely warm the space. A malfunctioning 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, check the thermostat to ensure it’s set right and the batteries aren’t dead.

If the problem continues, consider contacting an experienced HVAC company, such as JTech Mechanical, 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 a few steps you can take to troubleshoot before phoning a heating specialist. Check if the thermostat is set properly and the batteries are fresh. If the furnace still doesn't power on, check the circuit breaker or fuse box to make sure power is reaching the unit.

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

5. My Furnace Short Cycles

If your furnace is short cycling, it means it is turning on and off frequently at short intervals rather than running in regular cycles like it is designed to do. This can lead to inefficiency, more energy use and potential damage to your unit.

If you think your furnace is short cycling, the first step is to look at your unit’s air filter. Filters should be exchanged regularly 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 make sure  it’s set right and the batteries are good.

If those two things don’t work, it’s smart to call experts like the staff at JTech Mechanical. 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 Won't Stop Humming

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

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

7. My Furnace Is Making a Loud Noise

If your furnace is producing a persistent loud noise, it's important to deal with the issue right away to prevent further damage or potential safety hazards.  One common reason 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 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 working. Then, verify that the circuit breaker or fuse that goes to the furnace is functioning properly. If these basic checks don't fix the problem, you can check 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 do the job, call a professional for furnace repair.

9. My Furnace Is on but Not Igniting

Much like a furnace not turning on at all, a furnace that isn’t igniting can be the result of a plugged air filter or a tripped circuit breaker. So, examining the air filter and looking over your circuit breakers are a good place to start.

Other potential causes of a furnace not igniting could be a faulty igniter or faulty flame sensor. Indications of these include the furnace repeatedly making an attempt 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 JTech Mechanical.