Solved: Furnace Is Leaking Water and 8 Other Heating Problems

Whether it’s a leaky furnace or if you flick the switch to power up 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 typical furnace problems is crucial in deciding whether you can troubleshoot on your own or if you need professional assistance. By observing 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 aren't equipped with the necessary skills and tools, it's best to call an experienced HVAC company like Northwest Services. We can accurately identify 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 prevalent 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 completely draining away. This may be due to a plugged condensate drain line or a malfunctioning condensate pump. Another potential cause of water leakage from a furnace is a cracked heat exchanger, which can result in water—as well as dangerous gases—coming out of the furnace.

It is imperative to manage water leaks quickly to prevent more damage to your furnace. Reaching out to a professional HVAC technician like the crew at Northwest Services is recommended to diagnose and resolve the issue successfully.

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

If your furnace does not blow hot air, it's better to contact a professional HVAC technician to diagnose and fix the problem. They can offer an accurate assessment and recommend the proper 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 doesn’t have enough insulation, which can lead to heat loss and reduced efficiency. Another reason your furnace is falling short is because it’s too small for your home, so it can’t produce enough heat to effectively warm the space. A broken thermostat or ductwork problems can also result in uneven heating.

To deal with this, first assess your home’s insulation level and make sure it’s enough to insulate your home. Also, check the thermostat to see if it’s set right and the batteries aren’t dead.

If the problem won’t go away, consider calling an experienced HVAC company, such as Northwest Services, 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 Is Not Working

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

If there is power but your furnace won't blow hot air, the problem may lie with the ignition system or gas supply. In that case, it's a good idea to consult a knowledgeable HVAC professional for diagnosis and repair.

5. My Furnace Is Short Cycling

If your furnace is short cycling, it means it is turning on and off multiple times at short intervals instead of running in regular cycles like it should. This can result in inefficiency, increased energy consumption and potential damage to your heating system.

If you believe your furnace is short cycling, the first step is to pull out your unit’s air filter. Filters should be exchanged on a regular basis to ensure air flow, so if your furnace air filter is clogged with debris you should exchange it for a clean one—and make sure it is pointing in the right direction. Next, check your thermostat and verify  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 Northwest Services. Prompt 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 an issue with the electrical components or the blower motor. For this reason, if you hear your furnace making a humming noise, it is important to take action.

If the noise persists, it is better that you  get in touch with a professional HVAC technician.

7. My Furnace Is Noisy

If your furnace is producing a persistent loud noise, it's important to handle the issue right away to prevent further damage or potential safety risks.  One common cause of this 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 emit a squealing or rattling noise.

Due to the complexity of furnace systems and potential risks involved, it's better to consult with a heating and cooling specialist.

8. My Furnace Won't Start

If your furnace will not turn on, make sure the thermostat is set to the desired temperature, is in heating mode and the batteries are good. Then, verify that the circuit breaker or fuse controlling the furnace is functioning properly. If these basic checks don't take care of the problem, you can inspect 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 professional for furnace repair.

9. My Furnace Won't Ignite

Like a a furnace that will not on at all, a furnace that isn’t igniting can be caused by a clogged air filter or a tripped circuit breaker. So, checking 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 could be a faulty igniter or nonfunctional flame sensor. Signs of these include the furnace continually 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 simply fixed by HVAC professionals like the team at Northwest Services.