- HVAC
- Air conditioner
E0
Mitsubishi Electric E0 on an air conditioner: remote gets no data
Risk level
Low
Usually safe to check without specialist tools.
Urgency
Medium
Quick answer
On Mr. Slim PKA units with a wall remote, E0 means the remote is not receiving transmissions from the indoor unit. If you have two remotes, make sure one is set as main; then do a single reset and, if E0 persists, call a technician.
Safety first
Stop and check this first
- Do not take the wall remote apart or open the indoor unit to check the cable: the terminals share space with the unit's supply and Mitsubishi Electric requires every circuit to be cut before they are touched.
Safe checks you can perform
- Record E0 and the remote's state
- Main and sub setting with two remotes
- Single reset with start-up wait
- Remote wiring and check function
Leave these tasks to a qualified professional
- Do not attempt this professional task: Remote transmission cable inspection
- Do not attempt this professional task: Diagnosis with Remote controller check
- Do not attempt this professional task: Tracing interference on the line
What a technician must be able to justify
Technician visit
These are the steps they must carry out and show you. Tick them as they work: if steps are skipped, do not accept a part swap.
These are not instructions for opening or handling the equipment yourself. They are the checks that should support a technical conclusion.
Remote transmission cable inspection
What they doThe technician checks for loose or disconnected remote cable connections at the indoor unit and at the remote itself.
They must show youthe remote cable connections and its route to the unit.
In writingcode E0, connections corrected and estimated cable length.
Diagnosis with Remote controller check
What they doThey use the remote check function in the service menu to find out whether the remote responds properly.
They must show youthe message the remote check returns on screen.
In writingthe check result and any part replaced with its reason.
Tracing interference on the line
What they doIf the check points to noise, they follow the remote cable route and its proximity to lines or equipment that create interference.
They must show youwhere the remote cable runs and what was changed to move it away from the noise.
In writingnoise source found, correction applied and date.
Before accepting a part or repair
Nothing has been shown yet. Do not accept a part swap based on the code alone.
Follow these steps
Note: Follow the documented order. An error code identifies the affected system, but it does not prove by itself which part has failed.
Record E0 and the remote's state
- Who:
- you.
- How:
- E0 shows on the wired remote's screen; the manual's table gives it no blink pattern on the wireless remote. If the remote allows it, open the main menu and go to Error information to see the code and refrigerant address.
- Result that matters:
- a record that this is E0, the remote's own transmission alert.
- If the screen shows E0 steadily:
- move on to the steps below.
- If the screen shows PLEASE WAIT right after power-up:
- the manual treats that as normal for about 2 minutes of system start-up.
- Evidence to keep:
- a photo of the remote screen showing the code and the time.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Main and sub setting with two remotes
- Who:
- you, from the menu.
- How:
- if the unit has two wall remotes, open the main menu on each, go to Initial setting and look at the Main/Sub option. The manual says that with two remotes connected one must be the sub, and that E0 appears when all of them are set as Sub.
- Result that matters:
- confirming there is exactly one main remote.
- If both remotes read Sub:
- set one to Main from that menu or ask the technician to do it.
- If there is only one remote or the setting is already right:
- the problem lies in the cable or the circuits.
- Evidence to keep:
- a photo of the Main/Sub setting on each remote.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Single reset with start-up wait
- Who:
- you, at the fuse box.
- How:
- switch the unit off, turn off its breaker, wait until the remote screen goes fully dark and switch it back on. Allow about 2 minutes, the time the manual says the remote cannot be used during system start-up, before judging the result.
- Result that matters:
- whether E0 clears after a clean restart of the communication.
- If E0 no longer appears:
- write down the date and watch for a repeat.
- If E0 comes back after those minutes:
- stop resetting and have the wiring inspected.
- Evidence to keep:
- the reset time and how many minutes E0 took to return, if it did.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Remote wiring and check function
- Who:
- an HVAC technician.
- How:
- checks the remote cable is not loose or disconnected at the indoor unit, that total length stays within 500 m, that there are no more than 16 indoor units or 2 remotes and, if all is well, runs Remote controller check from the service menu.
- Result that matters:
- separating a cable fault from a remote or indoor board fault.
- If RC NG appears:
- the manual says to replace the remote; RC E3 or ERC 00-66 points to electrical noise.
- If RC OK appears:
- power is cycled to check, and if E0 returns the manual says to replace the indoor controller board.
- Evidence to keep:
- the remote check result plus the lengths and connections inspected.
Inspecting terminals and connections inside the indoor unit requires all power to be cut: technician only.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Still not solved
If the error persists, stop here. See what the technician must do and show you.
Where this code applies
A code is meaningful only inside the right product and version context.
Primary scope
- System
- HVAC
- Brand
- Mitsubishi Electric
- Product type
- Air conditioner
Known code variants
- Daitsu E0
- E 0
- Mitsubishi E0
- Mitsubishi Electric E0
- Mr. Slim E0
- PKA E0
What it means
According to service manual OCH639 (PKA-A24/30/36KA7 indoor units), E0 is a remote controller transmission error: the main or sub remote receives no normal transmission from the indoor unit at refrigerant address 0 for 3 minutes, or the sub remote receives no signal at all for 2 minutes. It is a wired remote communication alert, not a refrigerant circuit fault. Other equipment may use E0 in another way. E0 appearing does not by itself confirm that the remote or the board is broken.
Warnings and stop conditions
- Mediumeditorial warning
Do not take the wall remote apart or open the indoor unit to check the cable: the terminals share space with the unit's supply and Mitsubishi Electric requires every circuit to be cut before they are touched.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Symptoms and causes
Probable causes · in order
- Remote cable loose or poorly connectedCommon
Mitsubishi Electric lists first a contact failure on the remote controller transmission wire or a loose connection at the indoor unit.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
- Every remote set as subPossible
If no remote is set as main, the manual explains that the remote shows E0 while the outdoor board LEDs signal E4.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
- Remote wiring done wrongPossible
Miswired remote, total length above 500 m or use of a cable with three or more cores, which the manual says to avoid.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
- Faulty send or receive circuitPossible
A failure of the transmit and receive circuit in the remote itself or on the indoor controller board at refrigerant address 0.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
- Electrical noise on the remote lineLess common
The manual also cites interference entering the remote transmission wire and corrupting data between the remote and the unit.
Evidence: Mitsubishi Electric split-system heat pump service manual OCH639, indoor units PKA-A24KA7, PKA-A30KA7, PKA-A36KA7
Virtual technician
Does E0 still appear after these checks?
Answer a few questions to narrow down the likely cause and the safest next action. Guidance only - it never replaces a professional.
Sources and technical references
- 1
Mitsubishi Electric · 2016 · manual
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