Four Brands, Four Faults
E6 Error Code on Air Conditioners
Few codes show the brand problem as clearly as this one. An E6 error code air conditioner display means a compressor problem on a Daikin, a communication fault on a Mitsubishi Electric, a coil sensor on a Mitsubishi Heavy Industries unit and a hot compressor on an Actron. Here is how to tell which E6 you are facing.
Read This First
What Should You Do in the First Five Minutes?
Before you dig into meanings, a few quick actions keep you and the system safe. They also collect the information a technician needs. None of them involve opening a panel or touching wiring.
- Write down the code exactly as shown, or film the display for thirty seconds
- Switch the system off at the controller or remote
- If you smell burning or hear crackling, turn off the circuit breaker and leave it off
- Photograph the brand badge and the compliance label on the indoor unit
- Note what the system was doing, such as cooling on a hot afternoon or starting up
- Do not restart the system repeatedly while you work out what E6 means
That last point matters most for Daikin and Actron owners. On those brands, E6 relates to the compressor, and forcing restarts can turn a manageable repair into a major one. On the other hand, a Mitsubishi Electric E6 is a communication fault, where one careful reset is reasonable.
The Meanings
What Does E6 Mean on Each Brand We Could Confirm?
This page draws on manufacturer material, service documentation and our own brand guides. These are the four meanings we are confident about.
Daikin: Compressor Lock or Overcurrent
Daikin’s malfunction code chart describes E6 as a compressor motor overcurrent or lock. In other words, the compressor drew too much current or failed to turn when it should have. Listed causes include a defective compressor, a fault on the control board and a stop valve left closed. We have not written a separate Daikin E6 guide, but the Daikin code hub includes it in its quick reference.
Mitsubishi Electric: Indoor and Outdoor Communication
Mitsubishi Electric service manuals describe E6 as an indoor and outdoor communication error on the receiving side. The indoor board has not received a valid signal from the outdoor unit for several minutes. Our Mitsubishi E6 guide covers this meaning in depth.
Mitsubishi Heavy Industries: Indoor Coil Sensor
MHI documentation lists E6 as an indoor heat exchanger temperature thermistor anomaly. Put plainly, the sensor on the indoor coil is reading out of range. It is a sensor fault, not a communication fault. The same Mitsubishi E6 guide explains how to tell the two makers apart.
Actron: High Discharge Temperature
Actron associates E6 on its Que, Neo and L Series controllers with discharge temperature. Its fault reference describes it as discharge temperature running too high on ESP Platinum, Que Platinum and Advance systems, and notes a frequent link to low refrigerant on ESP Digital systems. See our Actron E6 guide.
Side by Side
How Do the Four E6 Meanings Compare?
Seeing them next to each other makes the differences obvious. Two involve the compressor, one involves communication and one involves a sensor.
Compressor Related E6
- Daikin, compressor overcurrent or lock
- Actron, discharge temperature too high
- Both are protective stops for the most valuable part of the system
- Both can be linked to refrigerant, airflow or electrical faults
- Both call for prompt booking and no repeated restarts
Signal and Sensor E6
- Mitsubishi Electric, indoor not hearing from outdoor
- Mitsubishi Heavy Industries, indoor coil sensor out of range
- Usually less mechanically risky than compressor faults
- Often linked to wiring, connectors or the sensor itself
- Still stop the system until repaired
If you own a Mitsubishi, the badge is essential. Mitsubishi Electric and Mitsubishi Heavy Industries are separate manufacturers that happen to share a name, and their E6 meanings have nothing in common. The Mitsubishi code hub explains how to tell them apart.
Not Confirmed
What About Samsung, Panasonic, Fujitsu and LG?
For these four brands, we could not confirm a single E6 meaning, so we will not offer one. Here is what we can say with confidence about each.
Samsung
On split displays, E6 is likely the first half of a four character code. Samsung broadly uses the 600 range for wired controllers, but we have not confirmed individual 600 series meanings, so check the full code on the Samsung hub. Older non inverter models show short codes that vary by model.
Panasonic
Panasonic uses a letter and two digits, mainly H and F codes, retrieved through a remote check routine. E6 is not part of that format as far as we could confirm. See the Panasonic hub.
Fujitsu
Fujitsu uses two character codes, often read from lamp flashes. Wired controllers may show E, a colon and two digits, which is different from E6. See the Fujitsu hub.
LG
LG uses CH followed by a number rather than E codes. We could not confirm any E6 meaning for LG. See the LG hub.
Hitachi, Toshiba, Haier and Carrier were not researched for this page. For any of them, the model number and a photo of the display are the fastest route to a reliable answer.
Finding Your Model
Where Do You Find the Brand and Model Details?
The process is the same whichever brand you suspect. It takes a few minutes, needs no tools, and it is the most useful thing you can do before booking.
Front of the Indoor Unit
The brand name is usually printed on the cover. Check carefully on Mitsubishi units for the word Electric or the words Heavy Industries.Side Label
Most wall splits have a compliance label on the right side. It lists the model number. Mitsubishi Electric wall units often start with MSZ, while MHI wall units often start with SRK.Wall Controller
Ducted owners should note the controller model. Actron controllers include Que, Neo, L Series and WC-02, and each handles codes slightly differently.Outdoor Unit Label
The outdoor unit carries its own label. Read it from a safe position without removing panels, and photograph it if the indoor label is faded.Paperwork
Installation invoices and warranty cards often list the exact model. They are worth checking if labels are hard to reach.
Owner Checks
Which Checks Are Safe and Actually Useful?
The right checks depend on which E6 you have. Each group below is safe for a homeowner, and none involve touching electrical parts or refrigerant lines.
Daikin or Actron E6
Clear the area around the outdoor unit and make sure the fan grille is not blocked. Clean dusty indoor filters. Then leave the system off and book, rather than restarting repeatedly.
Mitsubishi Electric E6
Check the switchboard and the outdoor isolator. Reset once by switching off the breaker for about five minutes. If E6 returns, book a technician to test the link.
MHI E6
Clean the indoor filters, since poor airflow can affect coil temperatures. Reset once. If the code returns, a technician needs to test the coil sensor and its connector.
Open more detail
Leave every cover in place. Compressor terminals, inverter boards and sensor connectors sit behind panels that carry mains voltage, and some boards hold a charge after power is removed.
If a technician finds the cause involves refrigerant, that work must be done by an ARCtick licensed technician under Australian rules. The technicians we send hold the licences their work requires.
Common Causes
What Usually Sits Behind Each Type of E6?
Causes differ by meaning. Below, we have grouped the usual suspects in rough order from simple to serious. A technician confirms which one applies through testing.
Behind a Compressor Type E6
On Daikin and Actron systems, the compressor is either drawing too much current, failing to turn, or running too hot. Simple contributors include a blocked or dirty outdoor coil and an outdoor fan that is not moving enough air. More involved causes include a low refrigerant charge, a closed service valve after installation work, a failing capacitor or drive component, and in the worst case a worn compressor.
Behind a Communication Type E6
On Mitsubishi Electric systems, the indoor board is not hearing the outdoor unit. Power to the outdoor unit may be off, the interconnecting cable may be damaged, or a terminal may have worked loose or corroded. Less often, the indoor or outdoor board has failed, sometimes after a power surge.
Behind a Sensor Type E6
On MHI systems, the indoor coil thermistor is reading out of range. The sensor may have failed, its connector may be loose or corroded, or the wire back to the board may be damaged. Occasionally the board’s input circuit is at fault.
Australian Conditions
Can Hot Summers and Coastal Air Bring On E6?
They can certainly contribute. Compressor type E6 codes are more likely during heatwaves, because the compressor works harder and runs hotter when outdoor air is already scorching. Afternoons over the high thirties in Adelaide, Perth and western Sydney are typical trigger days. A cramped installation, such as a unit boxed into a narrow side path, makes it worse.
Coastal suburbs bring salt air, which slowly corrodes outdoor terminals and connectors. That can cause intermittent communication faults on Mitsubishi Electric systems in beachside areas of Sydney, Perth and Adelaide. Humid conditions in Brisbane encourage similar corrosion.
Storms matter too. A nearby lightning strike or a brownout can upset boards and interrupt communication. Meanwhile, bushfire smoke and dust can clog filters and coils, reducing airflow and indirectly raising compressor temperatures. If E6 coincided with any of these, tell us when you book.
The Repair
What Does a Technician Do About E6?
First, the technician confirms the brand, model and controller, and pulls up the correct code table. With E6, that alone decides whether the next steps involve compressor diagnostics, cable testing or sensor measurement.
For compressor meanings, they inspect airflow, check the outdoor coil and fan, measure electrical values on the compressor circuit and, where needed, check refrigerant pressures. For the Mitsubishi Electric communication meaning, they check supply voltage at both units and test the interconnecting cable and terminals. For the MHI sensor meaning, they measure the thermistor’s resistance against the manufacturer chart and inspect its connector and wiring.
Once the fault is fixed, the system runs under load long enough to confirm E6 does not return. If refrigerant was involved, the technician also checks for leaks rather than simply topping up.
Should You Keep Using the System?
No. On every brand we confirmed, E6 stops normal operation for a reason. Leave the system off until it has been checked, especially on Daikin and Actron units where the compressor is involved.
Retrieving the Code
How Do You Read E6 if Your Unit Has No Display?
Plenty of wall splits have no screen. Instead, a lamp on the indoor unit blinks to signal a stored fault. The blink alone rarely tells you the code, so you need another way to read it.
On many Daikin remotes, a check function cycles through codes while the indoor unit beeps. A long beep marks the stored code. Mitsubishi Electric wall splits often report faults through a blinking operation lamp, and the number of blinks relates to the fault group. MHI and Actron systems with wired controllers usually show the code straight on the controller screen. Samsung units with a small display show four character codes in two halves.
If none of that works for your model, count the blinks in each group, note the pause, and tell us the pattern. A technician can read the stored code with the right tool. Please avoid pressing random button combinations, since some remotes enter installer menus that change settings.
After the Repair
How Can You Lower the Chance of E6 Returning?
Once the fault is fixed, a few habits help keep it fixed. They suit every brand, though they matter most where E6 relates to the compressor.
- Keep at least the manufacturer’s recommended clearance around the outdoor unit
- Clean indoor filters regularly, more often during smoke or dusty periods
- Book routine servicing so the outdoor coil and fan are checked
- Ask the technician to inspect outdoor terminals if you live near the coast
- Avoid setting extreme temperatures on the hottest days, which keeps the compressor under less strain
- Report any new noises or weak cooling early rather than waiting for a code
Our article on how often to service your air conditioner gives general guidance on timing.
Related Codes
Which Codes Are Close Cousins of E6?
Some codes often appear in the same fault history, or are easily confused with E6. Knowing them helps you read the bigger picture.
For example, Actron E8 is a fault with the discharge temperature sensor itself, while Actron E6 means the temperature that sensor reads is genuinely too high. Similarly, Mitsubishi Electric E9 is the outdoor side of the same communication link that E6 reports from the indoor side.
Book a Visit
When Should You Call About an E6?
For Daikin and Actron owners, call promptly, because compressor protection codes should not be left to repeat. For Mitsubishi owners, call if the code returns after one reset. In all cases, call straight away if you notice burning smells, smoke or harsh noises.
We book licensed technicians across the five mainland capitals and surrounding suburbs.
See our air conditioning service Australia page for how national bookings work. The error code library and the troubleshooting guide cover other codes and symptoms, and our Daikin and Mitsubishi service pages explain brand servicing.
Questions
Frequently Asked Questions
Why does E6 mean such different things?
Each manufacturer writes its own code list. There is no shared standard, so the same characters can describe a compressor fault on one brand and a sensor fault on another.
Is a Daikin E6 worse than a Daikin E5?
Both involve the compressor. E6 points to overcurrent or a lock, while E5 points to overload or overheat. A technician needs to test either one, and neither should be forced to restart.
My Mitsubishi shows E6 after a storm. What now?
If it is a Mitsubishi Electric unit, try one reset at the breaker. If E6 returns, book a technician to check the cable, terminals and boards.
Is an Actron E6 caused by low gas?
It can be. Actron links high discharge temperature to low refrigerant on some systems, but airflow and other faults can cause it too. A licensed technician confirms the cause.
Does Fujitsu use E6?
Fujitsu uses two character codes. We could not confirm an E6 meaning for Fujitsu, so note the lamp pattern or display and share it with a technician.
Can a dirty filter cause E6?
On MHI units, poor airflow can affect coil sensor readings, and on compressor type meanings it can raise operating temperatures. Cleaning filters is a sensible first step but rarely the full fix.
What should I send when I book?
Send the brand, model, controller type, full code, photos and a note about the weather and what the system was doing.
Need an E6 Checked?
Share your brand, model and code, and we will arrange a licensed technician in your area.
Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles