Why Is My Furnace Beeping?

You would certainly get extremely annoyed by a beeping sound if your furnace ever starts making it. But, in such a case, you should try to put your emotions aside and find the root cause of the problem.

The furnace can be making a beeping sound because the filter needs to be changed, the power is out, the sensor is dirty or defective, and there is excessive condensation in the system. The noise might also be an indication of low thermostat batteries.

In any case, you should act as soon as you hear the noise as any kind of sound produced by the unit is usually an indication of some sort of problem.

Why Is My Furnace Beeping?

Unfortunately, if you hear your furnace beeping, the chances are extremely high that something is wrong.

However, it is not always easy to determine what exactly has to be fixed, in case you’re a non-professional.

In a lot of cases, if your furnace is beeping, it is also going to have a blinking LED light.

The blower cover door usually has a small viewing hole. Come closer and write down the blinking pattern.

Furnace manuals come with a decode that you can use to figure out what’s going on.

For example, if you have a Lennox furnace, slowly flashing LED lights might mean that the blower motor isn’t operating, and so on.  

Tip: opening the furnace manual is always a good idea as there might be a detailed explanation of why your unit is making a beeping sound. 

What Else Can a Beeping Noise Mean?

  • The filter has to be changed
  • The remote batteries are low
  • The power is out
  • The sensor is defective
  • There is excess condensation in the system

Ignoring any sounds that are produced by your furnace is a bad idea as a minor issue can, later on, turn into a major problem. 

Your furnace won’t blow up as the newer models are programmed to shut down if there is ever a time when a serious technical error occurs. But you should definitely try to fix the root cause of the beeping noise as soon as possible.

How to Fix a Beeping Furnace?

The first thing that you have to do is make sure that the sound is coming from the actual furnace. The noise might be coming from a smoke alarm or a carbon monoxide detector.

So, switch the furnace off. If the sound goes away, then the problem is with the heating unit.

Warning! If your carbon monoxide detector went off, make sure to turn off all the sources of combustion, open the doors and windows, evacuate all the people from the space, and call a professional.

The Power Is Out

A beeping sound might indicate that the power is out. To fix the problem, check the circuit breaker.

Flip it from the ‘off’ to the ‘on’ position, if that is the case.

If necessary, you might have to reset the furnace. 

To reset an electric furnace, simply locate the reset button (it’s usually found inside the blower compartment) and press it down. Don’t forget to turn the power off before performing any manipulations.

If you have a gas furnace, then ensure that the pilot light is out, set the thermostat to the lowest possible temperature, turn off the power and the main gas supply, and re-ignite the pilot light.

Only after that, you can turn the main gas supply and circuit breaker back on, press and hold the reset button for half a minute, and, finally, raise the temperature on the thermostat.

The Sensor Is Defective

A faulty sensor might start to beep whenever the unit is on.

If the sensor is defective, you will, most likely, have to call a professional to replace the detail.

However, the sensor might simply be dirty and a lot of homeowners can take care of this problem on their own.

  • Shut off the power
  • Remove the head screw, so that the sensor can slide out
  • Carefully rub the metal rob with sandpaper
  • Use a paper towel to get rid of any dust that was left behind
  • Put the sensor back in place and check if the manipulation helped

Excess Condensation

Some furnaces have condensation alarms that are going to warn the owner if there is ever too much condensation in the system.

Even though it is normal for a lot of high-efficiency furnaces to create condensation, too much of it can be harmful. At one point, your unit might even start to leak.

This might be because of:

  • Problems with the condensate pumps
  • Blocked condensate drains
  • Some issues with the condensate line

Look for a clog or leaks in the water feed tube, drain line, water tap line, and the outside casing of the humidifier (if you have one).

In case you can’t get rid of the clog yourself, call a professional.

Old Filter

There are special furnace filter alarms that go off when it’s time to change your air filter.

In such a case, you should simply change the filter and the beeping is going to stop.

Changing this part of the unit regularly is incredibly important. A clogged or dirty filter reduces the lifespan of the system and its efficiency. 

Low Batteries

A thermostat operates with the help of batteries. Some devices will start making a beeping noise, once the batteries are close to dying.

Ideally, you should replace them every year. The beeping might start 1-2 months prior to that.

Furnace Alarms ; Sounds

A beeping sound is not the only noise that you can hear coming from your furnace.

You should definitely take note of any sounds and try to fix the root cause as soon as you detect them.

Why Is My Furnace Chirping?

You might hear chirping sounds at the beginning of the heating season. This is totally normal if you haven’t been using your furnace for a while.

But if the noises don’t go away in a few days, then there might be an issue with the fan belts. Simply replace this part of the unit and see if it helps.

Chirping can also mean wheel misalignment, loose motor mounts, and worn-out bearings. 

Why Is My Furnace Whistling?

Whistling is usually the sound of restricted airflow. It means that there is a clog of some sort in the system.

You might need to change the filter. If the filters are relatively new, then there should be a restriction somewhere in the ductwork.

By the way, leaks in the ducts can also make a whistling noise. So, make sure to check the whole system for leakage.

Why Can I Hear Loud Thuds Coming from My Furnace?

As soon as you turn your furnace on, you might hear a thud and that’s absolutely normal.

But if the sounds are too loud or persistent, then it looks like there might be a problem with the ductwork or an issue with the electronic ignition.

Only a highly experienced professional will be able to find the root cause. 

Other Furnace Noises to Watch Out For

·         Popping

As soon as the burner reaches the right temperature, it pops the excess gas or oil. However, if you continuously hear the unit popping, then it could mean that the burner is struggling to reach a temperature that is high enough.

Do you hear the sound, when the unit is off? Then your system needs ductwork maintenance as the ducts can pop when they expand and contract with the change of the temperature.

·         Rattling

A rattling sound can mean a lot of things, starting from a broken fan blade and problems with the motor and ending with loose debris.

·         Vibrating

Vibration in the system might be an indication of loose ductwork. While the air escapes the system, it will be making such a noise.

·         Dry Squealing

The most common cause for such a noise is bad bearings in the blower motor. Belts that need replacement might also be to blame. 

By the way, a broken or loose belt can be making a clanking sound when you turn the unit on or off. The belt is hitting other parts of the furnace causing even more damage, so calling a professional is vitally important.

To Sum Up

If you ever hear your furnace beeping, there are a few things that you can do.

Firstly, double-check if the sound is coming from the actual unit or a smoke alarm, for example.

Secondly, check the circuit breaker, thermostat, and filter – the chances are high that there is a problem with one of these parts. 

You can also attempt to replace the belts and fix the leaky ducts (if you have any), but even if the sound will go away after your manipulations, it doesn’t necessarily mean that you have managed to get rid of the problem.

If you want to sleep soundly, then make sure to invite a professional to inspect the furnace and take care of the root cause that is generating the sound.