Solved: Furnace Leaks Water and 8 Other Heating Issues

Whether it’s a leaky furnace or if you flick the switch to power up 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 vital in deciding whether you can troubleshoot on your own or if you need professional services. By monitoring the furnace's behavior, listening for peculiar noises and checking for signs of damage or blockage, you can narrow down the possible causes.

If you're not sure about the problem or aren't equipped with the necessary skills and tools, it's best to call a professional HVAC company like Precision Mechanical. We can accurately diagnose the issue and execute 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 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 could be due to a plugged condensate drain line or a failing condensate pump. Another potential 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 imperative to deal with water leaks immediately to prevent more damage to your furnace. Contacting a professional HVAC technician like the crew at Precision Mechanical is recommended to diagnose and resolve the issue effectively.

2. My Furnace Blows Cold Air/Lack of Heat

Some potential causes for a furnace blowing cold air or not blowing hot air are 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 mechanism.

If your furnace does not blow hot air, it's best to contact a trained HVAC technician to diagnose and fix the problem. They can give an accurate assessment and suggest the appropriate solution.

3. My Furnace Struggles to Keep Up

A common reason your furnace isn’t keeping up on a cold day is that your home lacks insulation, which can lead to heat loss and lower efficiency. Another reason your furnace is having difficulties 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 cause uneven heating.

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

If the problem continues, consider consulting with an experienced HVAC company, such as Precision Mechanical, who can assess 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 calling a heating specialist. Ensure the thermostat is set right 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 unit.

If there is power but your furnace won't blow hot air, 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 Short Cycles

If your furnace is short cycling, it means it is turning on and off often at short intervals as opposed to running in regular cycles like it should. This can result in inefficiency, higher energy bills and potential damage to your furnace.

If you think your furnace is short cycling, the first step is to check 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 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 best to call experts like the team at Precision Mechanical. Quick professional attention will help restore the proper functioning of your furnace and reduce the chance of more complications and high energy bills.

6. My Furnace Won't Stop Humming

If 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 critical to take action.

If the noise persists, it is best 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 quickly to prevent further damage or potential safety risks.  One common reason is a broken blower motor or fan, which can generate 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 best to contact a heating and cooling specialist.

8. My Furnace Can't Turn On

If your furnace will not turn on, make sure the thermostat is set to the preferred temperature, is in heating mode and the batteries are functioning. Then, verify that the circuit breaker or fuse that controls the furnace is sending power to the unit. If these basic checks don't take care of the problem, you can check 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 do the job, contact an expert for furnace repair.

9. My Furnace Is on but Not Igniting

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

Other potential causes of a furnace not igniting are a faulty igniter or faulty flame sensor. Symptoms of these include the furnace continually trying 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 professionals like the team at Precision Mechanical.