Fujitsu Inverter Air Conditioner: Troubleshooting Guide

Fujitsu inverter ACs are robust, energy-saving, and provide a higher comfort level than their non-inverter counterparts. But if they develop a mechanical problem, you’ll need to fix it if you want to keep the cold air flowing.

Common issues with Fujitsu inverter air conditioners include the failure to cool as expected, trouble coming on, and not responding to the remote control. You can fix some issues yourself, while others will require an HVAC professional.

Before you call an HVAC expert, use the following Fujitsu inverter air conditioner troubleshooting guide to address fundamental problems. You will also learn what inverter ACs are and how they differ from non-inverters. Let’s start!

What Is an Inverter AC?

An inverter air conditioner is an AC unit that can adjust the speed of the compressor motor installed in it.

Here’s how it works: when your home cools, the AC reduces the speed of the motor, which consequently lowers the speed of the refrigerant used to remove heat from the hot air leaving your home.

In non-inverter air conditioners, the speed of the compressor motor remains constant. When the temperature of your home goes down to the desired level, the compressor motor turns off, and when the temperature rises, the motor comes back on.

This repeated on and off action makes not only unnecessary noise but also consumes more energy. Inverter air conditioners fix this problem by adjusting the speed of the motor to mirror the temperature changes in your house.

How To Fix Problems With Fujitsu Inverter ACs

Fujitsu inverter air conditioners are great machines, but they aren’t immune to the wear-and-tear that comes from the constant use that most air conditioners are subject to.

There are three primary problems that your Fujitsu AC will be subject to: cooling issues, failure to turn on, and not responding to your remote. We’ll explain how to fix these problems below.

Cooling Issues 

If your Fujitsu AC isn’t cooling properly, there are a few things you can do to get the cold air flowing again.

Clean Dirty Air Filters

If your Fujitsu inverter AC is having trouble cooling your home, the first thing you need to check is whether the air filters are dirty. When the filter accumulates a lot of dirt, hair, and debris, it makes it difficult for cold air to pass through, keeping your home uncomfortably warm. 

To clean the filter, all you need to do is remove it from your AC unit and wash it with soap and water. Just keep cleaning until the filter is free of dust.

Fujitsu recommends cleaning filters for your inverter air conditioners every 400 hours. The unit will usually tell you when it’s time to clean, but you might need to clean it before the 400 hour mark if the unit has been sucking in particularly unclean air. 

If the filter is clean but the AC is still not producing cold air, move to the next troubleshooting tip. 

Tip: Make washing air filters a part of your AC maintenance routine. That way, you will always have a clean filter, and your unit will not experience airflow problems. 

Check Your Thermostat

If your Fujitsu inverter AC is connected to your home’s thermostat, the thermostat may be the source of the problem.

The first thing you should do is check to see the thermostat has power. If the screen is blank, the batteries may be dead. Replace dead batteries and see if it solves the problem.

However, for your AC to start a cooling cycle, the thermostat must have the correct settings. Check to see it is set to COOL. Also, the temperature displaying on the thermostat should be lower than the current room temperature. Usually, when the thermostat loses power, it resets itself, and you have to readjust the settings to make sure your AC works correctly.

Dirt accumulation can also make a thermostat malfunction and not communicate with the air conditioner. So, your Fujitsu inverter air conditioner troubleshooting should also include opening the back cover of your thermostat and removing any dust and dirt buildup. 

Close Doors and Windows

In the summertime, the air heats up pretty fast, so when you leave your windows or doors open, your home warms up just as quickly. If you are experiencing delays in cooling, it is probably because a window or door is open. Your AC is trying its best to keep your home cool, but the hot outdoor air makes it seem like the unit isn’t doing its job. 

When there is air coming from the outside, the AC also strains a lot, as it has to work for more extended periods to bring your home temperature down to your desired level. This puts it at risk of wearing out prematurely. You also pay crazy electricity bills. 

Check to see if you have any open doors or windows and close them right away. 

Remove Sources of Heat from the Room

Still experiencing cooling issues? Perhaps you have too many sources of heat in the room. Things like burners, heaters, cookers, or even computers can delay cooling and make you think your Fujitsu inverter aircon isn’t blowing cold air. Try moving any heating gadget to a different room and wait to see if this solves the problem. 

If you have tried all these fixes and your AC is still not cooling your home the way you want it to, consider calling in an HVAC expert. They will examine the evaporator coils, fan motor, and other components responsible for giving you cold air to see whether they are the culprits. 

Failure To Turn On

The primary reason ACs refuse to start is a tripped circuit breaker. If the breaker for your Fujitsu air conditioner is tripped, the unit won’t receive any current. Several things can cause this, including: 

• Faulty components: If any AC component starts to misbehave, the unit trips the breaker to prevent damage. 
• Electrical shorts: Some parts like the compressor motor or fan motor can run for hours. And while this helps keep your home cool, over time, this much movement wears down the insulation of the wires transporting electricity to the components, causing electrical shorts. More current passes through than the cables are rated for, which trips the breaker. 
• Loose wiring due to old parts: As your AC gets older, the wiring connecting the internal components starts to loosen. This could also trip the circuit breaker. 
• Power outage: If there has been a power outage in your area, the AC will shut off the breaker to keep it from damaging itself or the system. 

To troubleshoot a Fujitsu inverter air conditioner that has tripped a breaker, open the electrical box and locate your AC breaker. If it is turned off, turn it back on. But sometimes, the breaker may trip again immediately after it has been switched on, especially when the tripping is caused by a defective AC component. If this happens, don’t flip the switch back on; have it checked by an expert. 

Failure To Respond to the Remote

If your AC remote isn’t working, try the following: 

1. Move closer to the AC.
2. Remove any objects between you and the air conditioner. The remote sensor needs a clear path to communicate with your AC.
3. Open the back cover of the remote and rearrange the batteries. If this doesn’t help, remove the batteries and put new ones. 
4. If the remote still doesn’t work, remove the back cover again and check if you have inserted the batteries correctly. The + and – symbols on the batteries chamber will show you which way the batteries should face. 
5. Still not working? Maybe you don’t know your remote buttons the way you thought you did. Grab the user manual and go through the buttons and their functions once more. Hopefully, this will get your remote to function. If not, discuss the problem with your HVAC technician. 

Final Thoughts

Just like most cooling systems, Fujitsu inverter air conditioners can experience problems with cooling, turning on, or communicating with the remote control. For poor cooling performance, check to see the filters are clean, the thermostat is set right, doors and windows are closed, and there are no heating apparatuses in the room. 

Also, ensure the unit is getting power to avoid start-up problems, and the remote has working batteries to communicate better with the unit.

Chris Hewitt

Chris is a Texas-based freelance writer who loves the outdoors and working in his garage. When he’s not enjoying the Texas sun, he can be found tinkering with all sorts of things in his workshop.