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2024 Daikin Boiler Error & Fault Codes


Daikin heating systems are one of the most common in the UK. There are a number of reasons for this. Daikin boilers are reliable, energy efficient and easy to install, and most repair kits can fix all but the simplest problems. You're not looking at a complicated machine - you don't need to be an expert to understand how one works. Even so, it's still important that you know what to do when it goes wrong.

Daikin error codes are designed for easy identification at a glance. They're printed in large type on the display screen and grouped by section. For example, say that your problem is with the heating system. Each Daikin heating system has a separate fault code for each problem with the heating system. The individual codes are marked 10-, 11-, 12-, and so on.

D2CND Combi Gas Boiler Error Codes


The Daikin D2CND series of combi boilers are designed to provide you with a reliable domestic heating source and offer a number of energy saving features. The purpose of the error code is to help troubleshoot specific faults in your boiler.

The Daikin D2CND error codes are a series of blinking LED lights that display various problems with your boiler. They're very easy to understand once you've seen them a few times; don't worry if you're not familiar with them at first. Check out the table below and you'll learn everything you need to know really easily in about half a minute.

Fault Code Possible Cause
10-64Gas valve circuit error, try resetting boiler
10-65Gas valve current fault, try resetting the boiler
11-64Ignition error – possible fault with valve on the gas line due to it being open. Try resetting the boiler after the third unsuccessful ignition.
11-65Flame stabilisation error – wait for the boiler ignition trial
11-66Flame Signal loss in safety time – try to reset the boiler after 3rd unsuccessful ignition
11-67Flame loss during operation. This is a temporary error, wait for the boiler to re-ignite.
12-64Ion control deviation is too big – try resetting the boiler
12-65Ignition scott actuators error – try resetting the boiler
12-66Ion base value lower than the upper factory limit, try resetting the boiler
12-67Ion base value exceeds the upper factory limit – try resetting the boiler
12-68Ion base value differs from the previous value – try resetting the boiler
12-69Offset adaptation at limit
13-64Fan speed error – try resetting the boiler
13-65Fan speed error – try resetting the boiler
16-64Flue temperature signals overheating, the flue gas discharge path needs checking. Try resetting the boiler
1J-64High limit thermostat signalising overheating. Check the valve of the radiators in the heating, check if the Combi boiler water pressure is low, if it is then the heating circuit needs filling with water
80-01Return temperature sensor error – reset the boiler
81-01Flow temperature sensor error – try resetting the boiler
81-65Domestic hot water (DHW) temperature sensor error. The boiler will continue in operation but solar sensor has an error.
8A-46Freeze protection – the boiler won’t operate if flow temperature sensor reads a value that is less than 1°c
8H-65Flow temperature steep rise – the radiator valves may not be open enough to circulate water
E1-64Flame detected before burner operation – try resetting the boiler
E1-65Internal SCOT system error. Perform reset if needed
E1-66Calibration condition error, wait for burner to restart
E1-67Missing calibration – try resetting the boiler
E1-68Ion base value is outside the factory limits or saved incorrectly – try resetting the boiler
E1-69Parameter CRC fault – try resetting the boiler
E1-70Parameter CRC fault – try resetting the boiler
E1-71EK lockout failure – this is a permanent error
E1-72SCOT flame amplifier – reset the boiler
E1-73Printed circuit board (PCB) error – try resetting the boiler
H9-01Outside sensor fault – try resetting the boiler
HC-01Domestic hot water (DHW) temperature sensor error. The boiler will continue to operate but you need to contact a heating engineer
HJ-08High system pressure – the boiler needs to discharge water down to 0.8 bar
HJ-09Low system pressure – increase the system pressure to 0.8 bar
HJ-10Water pressure sensor fault
J6-01Flow temperature sensor overheating due to a blocking fault or a lockout error – the valves of the radiator heating circuit may have an issue or the water pressure is low and needs filling
J6-20Return temperature sensor overheating due to a blocking fault or a lockout error – try resetting the boiler
J6-21Return temperature is higher than flow temperature. Burner operates itself after a small amount of time but if the problem repeats you need to contact a heating engineer
JJ-64Supply voltage is below low limit
U2-01Supply voltage is above high limit, your boiler should continue to operate but you need to contact a heating engineer
U4-65OpenTherm room thermostat connection is defective – your boiler will continue to operation but the thermostat is out of operation
U4-66CAN-bus timeout
U4-67Remote reset supervision, switch off the power at the mains – if problem repeats contact a heating engineer
UA-64Blocking during boiler chip card (BBC) update
UA-65Printed circuit board (PCB) requires a boiler chip card (BCC) update
UA-66Boiler chip card ID (BCC-iD) of internal Electrically Erasable Programmable Read-Only Memory (EEPROM) is inconsistent
UA-67Boiler chip card (BCC) is missing
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