Solved: Furnace Is Leaking Water and 8 Other Heating Problems

Whether it’s a leaky furnace or if you flip the switch to start your heating system in the fall and it won’t start, common furnace problems can strike your home at any moment.

Regardless of the cause, learning how your heating system works and a little bit about some frequent furnace problems is essential in deciding whether you can troubleshoot on your own or if you need professional services. 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 an experienced HVAC company like Scott Temperature. We can accurately diagnose 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 prevalent 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 released during the combustion process is not effectively draining away. This may be due to a blocked condensate drain line or a failing 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—coming out of the furnace.

It is imperative to address water leaks immediately to prevent further damage to your furnace. Consulting with a professional HVAC technician like the crew at Scott Temperature is recommended to diagnose and resolve the issue properly.

2. My Furnace Blows Cold Air/Lack of Heat

Some likely 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 clogged 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 will not blow hot air, it's a good idea to contact a professional HVAC technician 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 common 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 reduced 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 broken thermostat or ductwork problems can also produce uneven heating.

To address this, first look at your home’s insulation level and make sure it’s enough to protect your home. Also, examine the thermostat to see if it’s set right and the batteries still function.

If the problem lingers, consider calling 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 Won't Work

If your furnace is not working, there are some steps you can take to troubleshoot before contacting a professional. Ensure the thermostat is set correctly and the batteries are not dead. If the furnace still doesn't turn on, check the circuit breaker or fuse box to make sure power is reaching the furnace.

If there is power but no heat, the problem may lie with the ignition system or gas supply. In that case, it's better to contact a knowledgeable 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 frequently at short intervals instead of running in regular cycles like it is designed to do. This can result in inefficiency, increased energy consumption and potential damage to your heating system.

If you think your furnace is short cycling, the first step is to check your unit’s air filter. Filters should be changed regularly to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and ensure it is pointing in the right direction. If that doesn’t do the trick, look at your thermostat and verify  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 crew at Scott Temperature. Immediate professional attention will help restore the proper functioning of your furnace and avoid additional complications and high energy bills.

6. My Furnace Hums All the Time

Whenever your furnace is making a humming noise, it often is an indication of problems with the electrical parts or the blower motor. Because of this, if you hear your furnace making a humming noise, it is crucial to take action.

If the noise continues, it is better that you  employ a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is emitting a constant loud noise, it's important to deal with the issue right away to prevent further damage or potential safety hazards.  One common cause of this is a malfunctioning blower motor or fan, which can make a grinding or screeching sound. Another potential 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 better to get a hold of 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 working. Then, see if the circuit breaker or fuse that controls the furnace is functioning properly. If these basic checks don't take care of 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 get the job done, phone 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 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 likely causes of a furnace not igniting include a faulty igniter or malfunctioning flame sensor. Symptoms of these include the furnace continuously trying 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 simply addressed by HVAC specialists like the team at Scott Temperature.