Solved: Furnace Is Leaking Water and 8 Other Heating Problems

Whether it’s a leaky furnace or if you flick the switch to turn on 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, knowing 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 services. By monitoring 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 Appalachian Heating. We can accurately identify 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 frequent heating issues:

1. My Furnace Is Leaking Water

A furnace can leak water for many reasons. One possibility is a condensate leak, where the water produced during the combustion process is not properly draining away. This may be due to a clogged condensate drain line or a malfunctioning 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—escaping from the furnace.

It is important to manage water leaks immediately to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Appalachian Heating is recommended to diagnose and resolve the issue effectively.

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

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

If your furnace won’t blow hot air, it's best to contact a trained HVAC tech to diagnose and fix the problem. They can provide an accurate assessment and recommend the appropriate 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 doesn’t have enough insulation, which can result in heat loss and lower efficiency. Another reason your furnace is struggling is because it’s not powerful enough for your home, so it can’t make enough heat to effectively warm the space. A defective thermostat or ductwork problems can also produce inconsistent heating.

To correct this, first check your home’s insulation level and make sure it’s enough to keep warm air in and cold air out of your home. Also, examine the thermostat to ensure it’s set right and the batteries aren’t dead.

If the problem won’t go away, consider consulting with an experienced HVAC company, such as Appalachian Heating, who can inspect 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 few steps you can take to troubleshoot before phoning a pro. Check if the thermostat is set properly and the batteries are fresh. If the furnace still doesn't start, check the circuit breaker or fuse box to ensure power is reaching the unit.

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

5. My Furnace Turns On and Off

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

If you believe your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be exchanged regularly 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. 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 smart to call experts like the team at Appalachian Heating. Immediate 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 Hums All the Time

If your furnace is making a humming noise, it often is a symptom of a malfunction with the electrical elements or the blower motor. Therefore, if you notice your furnace making a humming noise, it is important 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 Is Making a Loud Noise

If your furnace is making a constant loud noise, it's important to deal with the issue quickly to prevent further damage or potential safety risks.  One common cause of this is a broken blower motor or fan, which can generate 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 safer to consult with a heating and cooling specialist.

8. My Furnace Won't Start

If your furnace refuses to turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are functioning. Then, see if the circuit breaker or fuse that controls the furnace is working right. 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 do the job, contact a heating specialist for furnace repair.

9. My Furnace Is Not Igniting

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, checking the air filter and assessing 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. Indications of these include the furnace continually attempting to ignite without success, a lack of heat production or the furnace is making a burning or gas smell. Both of these issues can be very easily addressed by HVAC professionals like the team at Appalachian Heating.