Mitsubishi Ecodan Heat Pump Fault Codes

F3

Low pressure switch failure – check connection on the board and continuity of switch

F5

High pressure switch failure – check connection onto board and continuity of switch

F9

Both pressure switch contacts are open at the same time

EA

Mis-wiring fault between FTC and Ecodan – check S1,S2,S3 also check voltages and comms

EB

Mis-wiring fault between FTC and Ecodan – check S1,S2,S3 also check voltages and comms

EC

Unit cannot finish start up process – generally caused by a comms fault

U1

Ecodan high pressure fault – mainly caused by incorrect water flow rates – check with flow setter

U2

Ecodan high compressor discharge temperature – mainly caused by refrigerant shortage or dirty condenser

U3

Ecodan discharge thermistor problem – mainly caused by TH4 discharge thermistor – open/close circuit

U5

Inverter heat sink overheat protection (W50 and W85 models 77°C, HW140 model 95°C – reduced air flow through Ecodan – faulty fan motor

U6

Inverter/Compressor over current – system indicates possible IPM error

U8

Ecodan fan motor problem – mainly caused by DC fan motor being disconnected, connected or obstructed with the power on or possible main board fault

U9

Over voltage or under voltage – mainly caused by either CN2 or CN5 loose or disconnected or decrease of mains power supply

UD

Overheat protection TH3 > 70°C or 63HS < 70°C saturation temperature

UF

Compressor over current/Compressor lock – occurs within 30 seconds of compressor start

UH

Abnormal running current – 40A detected during operation – check CN5 connections

UL

Open circuit (63L)

UP

Over current detected after 30 seconds of operation – do an inverter test to determine outputs balanced

E0

Transmitting Error PAR W21 – check refrigerant address on SW1 of Ecodan

E1

Faulty controller

E3

Transmitting Error (PAR W21) – check refrigerant address on SW1 of Ecodan

E4

Receiving Error (PAR W21) – check refrigerant address of SW1 on Ecodan

E5

Receiving Error (PAR W21) – check refrigerant address of SW1 on Ecodan

E6

Indoor / Outdoor communication error – mainly due to Ecodan being powered up before FTC(2)

E8

Indoor / Outdoor communication error – mainly due to Ecodan being powered up before FTC(2)

E9

Indoor / Outdoor communication error – mainly due to Ecodan being powered up before FTC(2)

EF

Non-defined error code – noise interference – power down Ecodan for 30 seconds then switch back on

ED

Serial communication fault between Ecodan main board and Ecodan inverter board – mainly due to loose CN2 or CN5 cable

P1

Flow temp sensor fault – TH1 not connected, short or open circuit

P6

Over heating at heat exchanger – lack of water flow, air in the system, flow rate incorrectly set, blockage or pump problem

P8

No temp change at plate heat exchanger – problem with flow rate (too high) – incorrect sizing of system

P9

TH5 Fault – TH5 not connected, short or open circuit, FTC not configured for heating only

PE

Inlet water temp fault – TH32 is below 10°C whilst compressor is in operation – possible thermistor out of range, short of gas, incorrect sizing of radiator or problem in the water circuit (blockage, pump failure etc)