Mini Split Error Codes: E1, E6 and EC by Brand

By Ray Bennett · Updated 2 October 2026 · 5 min read · Checked against the makers’ own manuals

Short answer

Mini split codes are not shared between brands. E1 is a communication fault on MrCool and Senville, high pressure on Gree, the outdoor board on Daikin and a room sensor on Pioneer. E6 and EC differ just as much. A few things do repeat: CL means clean the filters, and a multi zone system with one room on heat and another on cool shows a mode conflict.

A mini split shows a code on the indoor unit’s display, or blinks its lights, when it stops. The first thing to know is that the codes are not shared between brands. E1 on one brand and E1 on another can be completely different faults.

This page brings together what each maker’s own documents say, as quoted on this site’s brand pages. It shows where the brands disagree, the few things that do repeat, and which page has your unit’s full list. Every brand-specific line here comes from the document cited on that brand’s page.

Before you start

What to carry: a torch, the remote and your phone for a photo. Five minutes.

Gas or electric? Electric. A mini split is a heat pump, with an indoor head and an outdoor unit.

Find the brand and the series. The brand is on the front of the indoor unit, and the model is on a label on the unit. Some brands use different codes on different series: Pioneer’s WYT series uses E codes, and other Pioneer series use EH and PC style codes.

Watch it twice. Mitsubishi says to check a blinking pattern for at least two full cycles before deciding what it is.

Breaker off before anything more than the remote. Burning smell, odd noise, water or a tripping breaker. Daikin and Gree both say to switch off at the breaker and call the installer or a technician.

Power stays in the unit. MrCool says to leave the breaker off for 15 minutes before opening anything, so the unit is fully de-energized.

Same code, different fault

E1 and E6 on six brands, each from that maker's own documents. Read your brand's list, not a general one.

Code	What it means, by brand
E1	Indoor and outdoor units not communicating on MrCool and Senville. High pressure protection on Gree. The outdoor control board on Daikin. The indoor room temperature sensor on Pioneer’s WYT series.
E6	Indoor and outdoor units not communicating on Gree. The compressor failed to start on Daikin. The indoor fan motor on Pioneer’s WYT series and on LG, where E6 goes with CH10.
EC	A refrigerant leak or low charge on MrCool. Outdoor communication failure on Pioneer’s WYT series.

The things that do repeat

Four things several makers agree on: the filter reminder, the mode conflict, dirty filters behind pressure codes, and a long power off.

Check 1Free, twenty minutes

Work the checks several brands share

CL: clean the filters. Senville and Pioneer both use CL as a filter reminder, not a fault. Fujitsu’s version is the Economy light flashing on its own. Clean the filters and it goes.

A mode conflict on multi zone. One outdoor unit cannot heat one room and cool another. Gree shows E7, LG shows CH07, Senville shows two dashes, and Mitsubishi’s multi zone units show it with their lamps. Put every indoor unit on the same mode.

Dirty filters behind pressure codes. Gree’s guide puts dirty filters first for E1 and E3, and Daikin names a clogged filter as the first cause of A5: what a dirty filter does to a mini split.

A long power off. For several of its codes, MrCool’s first step is the breaker off for 15 minutes, then back on. Senville’s reset for a communication error also starts at the breaker.

Codes that are lights, not letters

Check 2Free, five minutes

Count the lamps

Fujitsu. Its indoor unit counts out codes on its lamps: the Operation lamp gives the first digit and the Timer lamp the second.

Mitsubishi. Its wall units blink the operation lamp in groups, with a pause of about two and a half seconds between them.

Both. Count at least two full cycles, then look the count up on the brand’s own page below.

Find your unit’s full list

Brand	How it shows codes	The full list
MrCool	Two character codes, or EL, EH and PC codes	MrCool codes
Senville	EL, EH, EC and PC codes	Senville codes
Pioneer	E, P and CL codes on the WYT series	Pioneer codes
Gree	E, F, H and C codes	Gree codes
Daikin	Letter and number codes read with the remote	Daikin codes
LG	CH codes, or short codes on some displays	LG codes
Fujitsu	Lamp counts	Fujitsu codes
Mitsubishi Electric	Blinking lamp groups	Mitsubishi blinking light

When there is no code at all

Check 3Free, ten minutes

Check the basics

It will not start. Power, the remote’s batteries and mode, and the breaker: why a mini split will not turn on.

It runs but does not cool or heat. Filters, the mode and the outdoor unit: a mini split that is not cooling and one that is not heating.

Water from the indoor head. Usually the drain: why a mini split leaks water.

Questions people ask

What does E1 mean on a mini split?

It depends on the brand. On MrCool and Senville it is a communication fault between the units, on Gree high pressure, on Daikin the outdoor board and on Pioneer’s WYT series a room sensor.

What does E6 mean on a mini split?

On Gree the units are not communicating, on Daikin the compressor failed to start, and on Pioneer’s WYT series and LG it is the indoor fan motor.

What does EC mean?

On MrCool, a refrigerant leak or a low charge, which needs a technician. On Pioneer’s WYT series, an outdoor communication failure.

What does CL mean on a mini split?

On Senville and Pioneer it is a reminder to clean the filters, not a fault.

Why does my multi zone mini split show a code when one room heats?

One outdoor unit cannot heat and cool at the same time. Set every indoor unit to the same mode and the mode conflict clears.

How do I reset a mini split after a code?

Most have no reset button. Switch it off at the breaker for a while and back on. MrCool gives 15 minutes for several of its codes.

Sources: The makers' own documents, as cited on this site's brand pages: Fujitsu, LG, MrCool, Daikin, Gree, Senville, Pioneer and Mitsubishi Electric