Ecodan Heat Pump Fault Codes

Making your home more energy efficient with heat pumps

Ecodan 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
U4
Open or close circuit Ecodan thermistors (TH3, TH32, TH33, TH6, TH7, TH8) – open or close circuit or disconnected from main board
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 – < 1A or > 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)

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