Common Furnace Problems and How to Fix Them
Posted by Moore Home Services
HVAC Basics
A furnace that is working consistently and properly is key to keeping the temperature in your home comfortable throughout the year. Proper furnace maintenance is a great way to avoid any surprise issues in the middle of winter. Regardless, sometimes issues pop up that signal the need for help. Here are some of the most common furnace problems and how to fix them on your own.
The Blower is Always On
If you notice that the blower on your furnace is constantly running and never seems to turn off, there are two things to check. Confirm that the thermostat is set to the fan setting. Leaving it on the auto settings means the fan is running, but no air is being produced.
If that doesn’t clear anything up, your next step is to check the fan limit switch. The limit switch is a safety measure. When your unit overheats, the fan limit switch will shut down the system. There are a few things that can cause this. The first being your system is a bit older and might truly be overheating.
A few other things could also trigger the limit switch. If it were to get too dirty, the limit switch is not able to function properly. A simple cleaning should be just fine. A misfiring limit switch could also be attributed to a dirty air filter. This is an easy fix. Just remember to regularly check and change your air filter.
There Is Not Enough Heat
When your furnace is running but your home still is not feeling the heat, first check the settings on the thermostat. Sometimes a simple bump or unwanted adjustment while dusting in the area may have occurred, which could change the set temperature.
Next, are all your vents open? A closed vent means blocked airflow and in turn, no heat in your home. You should also never intentionally block or close a vent.
Modern furnaces are made to make enough heat for your whole house. When a vent is closed, your furnace is still making that air, but the excess air has nowhere to go. Instead, the extra air could increase the pressure so much in your HVAC system that a duct could break, or your system could shut down from too much pressure.
The next step should be to check your air filter. When was the last time it was replaced? A clogged or dirty filter will prevent air from flowing properly.
The Furnace is Short Cycling
We’re sure you’re starting to see a theme here. One of the major reasons a furnace could be short cycling is because of a dirty or overfull air filter. A dirty air filter can trap heat treated air. Meaning your furnace can fill with warm air that can’t make it to the rest of your house.
This trapped air can cause your furnace to overheat and shut down before finishing a full cycle. It can also trigger the fan limit switch we mentioned earlier.
It’s also important to check your thermostat. It’s common for homeowners to forget to switch it over to heating mode at the start of the season.
Your Furnace Keeps Turning Off
If your furnace keeps turning off, start by checking the thermostat. At the start of the cooler season, many homeowners set a temperature that’s too low for a full cycle. This could be one reason why your furnace keeps turning off.
Your next step should be to check the air filter. Make sure it’s clear enough for the season. A dirty or overfull air filter should be replaced as soon as possible.
Finally, take a look at the furnace’s flame sensor. The flame sensor is an important safety component of your system. It detects how much fuel is going into your system. When the flame sensor detects too much gas, it will shut down the entire system to keep it from exploding.
If your flame sensor is not working, call a professional to address the furnace repair, as it is a more complicated fix.
The Thermostat is Not Working
If your thermostat is not showing the temperature, check that the batteries are working. This is a simple repair you can take on yourself.
Think of your thermostat as the remote control for your entire system. If it doesn’t work, neither will your HVAC system. Sometimes a fresh pair of batteries will do the trick. You can also reset the thermostat by turning it to off and then back on after a few minutes.
The Pilot Light is Out
This one is mostly for older furnaces. It’s simple to check the pilot light. Just look at your furnace, there should be a very small window where you can see if the pilot light is on or off.
Keep in mind, your furnace is completely unable to make warm air if the pilot light is out. To relight it, start by turning off your furnace. Next, simply find the front panel of your furnace. Open the small door and behind it, you will locate the pilot light or gas valve. Hold down the small red button for a moment and then release it. Make sure you have a long lighter or match to actually spark a flame. This will restart the pilot.
Turn your furnace back on and assess the result. If it does not relight, you may need to call a furnace repair professional for help.
Know When to Ask for Help
Sometimes, furnace problems are bigger than we can handle. When this happens, there is no shame in calling a professional—like the ones at Moore Home Services—for help.
The important thing is calling for help before you do any big damage. Call the number at the top of the screen or click here to schedule an appointment online.
