Double Letter Code Lookup
EE Error Code on Air Conditioners
An EE error code air conditioner display is best known on Actron systems with the WC-02 wired controller, where it is a water level alarm. That means condensate is not draining and the unit has stopped to prevent an overflow. Other brands either do not use EE or use it in limited, model specific ways. Below, we explain what is confirmed and what to do if water is involved.
Act Quickly if Water Is Present
Should You Switch Off Straight Away?
If you have an Actron with a WC-02 controller and you can see water, yes. Turn the system off at the controller, place a bucket or towels under any drip, and keep people away from wet ceilings. If water is near light fittings, power points or the indoor unit’s electrics, switch off at the breaker too.
Water damage builds quietly. A ceiling can look fine for hours and then sag suddenly once the plasterboard is saturated. So even if the leak looks small, treat it seriously.
Also think about where the indoor unit sits. A wall split above a bed or a ducted unit above a living area needs faster action than a unit over a tiled laundry. Move valuables, electronics and rugs out of the way while you wait for help.
If there is no visible water, you still have time to work through the brand checks below before booking. The aim is to confirm which brand table applies, because EE does not mean the same thing everywhere.
The Brand Breakdown
What Does EE Mean on Each Brand?
We list a meaning only where we confirmed it in manufacturer documentation or in our own checked brand pages. Everywhere else, we say so clearly.
Actron: confirmed, water level alarm
Actron’s help information for the WC-02 controller links EE to a water level alarm. Its product fault reference describes EE on the WC-02 table as the drain tray being full, and on Serene systems as a water level alarm fault. This applies to WC-02 controlled products such as Serene and UltraSlim, not to the larger Que or Neo ducted controllers. Read the Actron EE guide.
Mitsubishi Electric: limited, model specific
A Mitsubishi Electric error code list we reviewed uses EE on certain networked controls for a communication fault between M-NET adapters. That applies to commercial and networked systems. We could not confirm a single EE meaning for residential wall splits, so ask a technician to check it against your model. See the Mitsubishi code library.
Mitsubishi Heavy Industries: not confirmed
MHI codes almost always begin with E followed by a number, such as E9 or E36. There is no confirmed EE meaning for MHI.
Daikin: not listed
Daikin’s own error code reference does not include EE in the entries reviewed. Use the Daikin code library and the remote check function to find the stored code.
Panasonic: different format
Panasonic codes are H or F followed by two digits. EE is not part of that scheme. See the Panasonic code library.
Samsung: not confirmed
Samsung inverter codes generally use E or C plus three digits. We could not confirm EE as a Samsung fault code. Visit the Samsung code library.
Fujitsu: different format
Fujitsu codes are two characters, mostly digits, read from lamps or a wired controller. We could not confirm EE. See the Fujitsu code library.
LG: different format
LG split and ducted systems use CH plus a number. Drainage on many LG indoor units is CH04. We could not confirm EE on LG air conditioners. See the LG code library.
How Condensate Works
Why Does an Air Conditioner Make Water at All?
Cooling and drainage go hand in hand. Warm, humid room air passes over the cold indoor coil, and moisture condenses on the fins, much like water beads on a cold glass. That water drips into a tray and leaves through a drain pipe.
Some installations rely on gravity alone. Others use a small pump to lift water up and away, which is common on ducted units in roof spaces, cassettes and units mounted far from an outside wall. A float switch in the tray watches the water level. If the level rises too far, the switch tells the board to stop cooling.
The float switch is a simple device, usually a small float that rises with the water and opens or closes a contact. Because it is so simple, it is very reliable, but sludge can jam it in either position. A jammed switch can cause a false alarm, or worse, fail to raise one.
On Actron WC-02 systems, that is exactly the moment EE appears. The alarm protects your ceiling, walls and the unit’s own electronics by stopping the flow of new condensate.
Likely Causes
What Usually Causes a Water Level Alarm?
The causes range from simple blockages to failed parts. The list below runs roughly from the usual to the less common.
Blockage causes
- Slime, algae or dust sludge building up in the drain tray
- A blocked drain outlet outside, often from dirt, insects or garden growth
- A kinked, crushed or sagging drain line
- A drain line that has been disturbed during renovation or roof work
Component causes
- A drain pump that has failed or is clogged
- A float switch that is stuck or faulty
- Wiring to the pump or float switch that has come loose
- An indoor unit that is not level, so water pools at the wrong end of the tray
New installations have their own risks. If the drain line was run without enough fall, or the pump was set too low, problems can appear in the first humid weeks after installation. Older systems, on the other hand, tend to suffer from years of sludge build up.
Dirty filters can contribute too. They reduce airflow, which can make the coil run colder and, in some conditions, produce more water or allow ice to form and then melt in a rush.
Owner Checks
What Can You Safely Check for EE?
Several useful checks need no tools and no access behind covers. Stop at once if water is near electrics or you see damage to wiring.
Confirm the controller
Check that your Actron uses a WC-02 controller. If it is a Que, Neo or L Series controller, EE is not the code table you need.Look for water
Check the ceiling, walls and floor near the indoor unit. On ducted systems, look around the return air grille and any ceiling access hatch.Find the drain outlet
Follow the drain pipe to where it ends outside, often near a gully or garden bed. Clear dirt, leaves or insects from the end.Clean the filters
Remove and rinse the filters if they look dusty, then let them dry fully before refitting.Wait, then restart once
Leave the system off for a while so any water can settle, then restart once and watch whether EE returns.
Please do not open the indoor unit to tip out the tray, and never bridge or disconnect a float switch. Bypassing the switch removes the only thing stopping an overflow.
Identify the System
How Do You Know Which Brand and Controller You Have?
EE is one of the codes where the controller matters as much as the brand. Actron in particular uses different code tables for different controllers.
Check the controller
Look at the wall controller shape and screen style, and any model name printed on it or in the manual. Photograph it while the code is showing.
Check the indoor unit
The compliance label lists the brand and model. On ducted systems the indoor unit is often in the roof space, so use the outdoor label instead.
Check the paperwork
Installation documents usually list both the system model and the controller. Keep them handy when you call.
Remember that a home can have more than one system. A newer wall split might sit alongside an older ducted Actron, each with its own controller and code table. Check the controller that is actually showing EE.
If you are still unsure, a clear photo of the controller showing EE is usually enough for a technician to identify the system.
Licensed Work
What Does a Technician Do for an EE Alarm?
A water level alarm usually needs the indoor unit opened, which means working near mains voltage and often in a roof space. The technicians we send hold the licences their work requires.
Clear and flush the drain
The tray and line are cleaned and flushed. Many technicians also treat the tray to slow future slime growth.
Test the pump and float switch
Where a pump is fitted, it is tested under load. The float switch is checked for free movement and correct operation.
Check the fall and level
The drain line should fall steadily away from the unit. The technician checks for sags, kinks and an indoor unit that has shifted out of level.
Run a test
Water is introduced to the tray, or the system is run in cooling, to confirm the drain clears and the alarm stays off.
Equivalent Drain Codes
What Is the Drain Fault Code on Other Brands?
Many people searching for EE really want to know what a drain problem looks like on their own brand. Every manufacturer has a drain related code, but very few call it EE. These are the equivalents we have confirmed in our brand guides.
- Actron WC-02 systems use EE for the water level alarm.
- Mitsubishi Heavy Industries uses E9 for drain trouble on its wall splits and cassettes.
- Mitsubishi Electric uses P4 for an open float switch circuit and P5 for drain overflow protection on pumped units.
- Daikin uses A3 for a drain level problem detected by the float switch.
- Fujitsu uses code 53 for a drain pump fault on cassettes, many ducted units and some floor models.
- LG uses CH04 for drainage on many indoor units.
Each of these codes has its own trigger and its own response, so follow the linked brand page rather than assuming they behave identically. Still, the owner checks are similar across the board. Look for water, check the drain outlet, clean the filters and avoid repeated restarts.
Ceiling Damage
What If Water Has Already Come Through the Ceiling?
An overflow from a ducted or cassette unit can soak plasterboard before the alarm trips, particularly if the float switch was slow to react. If you see staining, bulging or drips, act carefully.
Immediate steps
- Turn the system off at the controller and the breaker
- Keep people and pets out from under the wet area
- Place containers under any drips
- Switch off lighting circuits if water is near light fittings
Next steps
- Photograph the damage for your records and any insurance claim
- Book an air conditioning technician to fix the drain fault
- Arrange a ceiling repairer once the source is fixed
- Ask an electrician to check any wet light fittings
Do not poke holes in a bulging ceiling yourself unless you are sure no wiring is nearby. The technician will fix the drain, but plaster and electrical repairs may need other trades.
Humidity and Seasons
Why Does EE Appear More in Humid Weather?
The more humid the air, the more water the indoor coil pulls out of it. During long sticky spells in Brisbane and Sydney, drain systems handle far more water than on a dry Perth or Adelaide day. A partly blocked drain that coped in spring can overflow in the first humid week of summer.
Melbourne sees humid spells too, especially during warm, stormy weather. Meanwhile, bushfire smoke and dust can clog filters and coat the coil, adding fine sludge to the drain tray.
Roof space heat also matters. Pumps and float switches in hot ceilings across all five cities work in harsh conditions, which shortens their life. Regular servicing that includes a drain flush is the best way to stay ahead of EE.
Prevention
How Can You Reduce the Chance of EE Returning?
Drainage problems are among the most preventable air conditioning faults. A little routine care goes a long way.
- Clean the filters regularly, more often during smoky or dusty periods.
- Check the drain outlet outside every few weeks during summer, and keep garden beds clear of it.
- Book regular servicing that includes cleaning the drain tray and flushing the line.
- Ask for the drain line to be checked after any roof work, renovation or ceiling repair.
- Let us know if you hear the drain pump running constantly, which can be an early warning sign.
Our article on how often to service your air conditioner covers servicing intervals in more detail.
Booking
How Do You Arrange a Visit for an EE Code?
Rapid Air Cooling books and dispatches independent licensed technicians. We are not an Actron dealer and we do not claim accreditation with any manufacturer.
Find local information on our city repair pages: Sydney air conditioner repair, Melbourne air conditioner repair, Brisbane air conditioner repair, Perth air conditioner repair and Adelaide air conditioner repair. Our home page explains our air conditioning service Australia wide.
When you call, mention whether water is visible, where the indoor unit sits, and whether there is a safe roof access hatch. Those details help us prioritise and brief the technician.
Questions
Frequently Asked Questions
What does EE mean on an Actron?
On WC-02 controlled systems such as Serene and UltraSlim, EE is a water level alarm. The drain tray is full and the system has stopped to prevent an overflow.
Does EE mean the same on Actron Que or Neo controllers?
No. Those controllers use a different code table with E followed by a number. EE belongs to the WC-02 table.
Is EE a Mitsubishi Electric code?
A Mitsubishi Electric list we reviewed uses EE for an M-NET adapter communication fault on certain networked controls. We could not confirm a residential wall split meaning.
Can I keep using the system with EE?
No. Leave it off until the drain is cleared. Restarting repeatedly adds more water to an already full tray.
Can I clear the drain myself?
You can clear the outside end of the drain pipe. The tray, pump and float switch are inside the unit and need a licensed technician.
Why did EE appear after roof work?
Roof and ceiling work can crush, kink or disconnect drain lines. Mention the work when booking so the technician checks the line first.
Related Reading
Which Other Pages Should You Check?
Water Level Alarm on Your Controller?
Switch off, catch any drips and give us a call. We will book a licensed technician to clear the drain.
Reviewed by AC repair and service specialist on 22 October 2026. How we write our articles