Daikin Boiler Error Codes, Causes & How To Fix

Daikin boiler error codes and faults – What they mean & how to fix

Boiler error codes are the shorthand way of quickly working out what’s causing your heating system problems. While all manufacturers use error codes, what each one is, and its meaning varies from model to model.

Broken boiler? – Get a fixed price in 20 seconds online here

So, whether that means that while Daikin Altherma problems are similar to those from, say, Worcester Bosch or Alpha, the error code will be different.

If you have boiler cover in place already then, a quick call to the customer service centre will have someone heading out to see what’s going on. If you don’t have cover and your boiler is out of warranty, things can, unfortunately, get pricey.

Do though check through our guide on the different errors as with some you might be able to fix the fault yourself and have everything working again in no time at all.

Common Daikin Boiler Error Codes & Faults

Some boiler problems occur more often than others. So, we’re going to focus on the most common Daikin error codes first, and then if you can’t see what you’re looking for, you’ll be able to find the code within our comprehensive list at the end of this article.

You may not need a new boiler just yet.

How to fix an u4 error code

Two different issues can cause the Daikin U4 fault. First of all, there’s U4-65 which comes up when there are problems with the connection with the room thermostat. Then there’s U4-66 which relates to a timeout on the CAN-bus.

For both of these, it’s worth trying a reset of your boiler to see if that clears the fault.  If you’re not sure how to do that, take a look at your manual for instructions. To download a copy of the manual from Daikin – click here and then select your boiler model.

How to fix an 8a fault code

If the outside temperature has plummeted, then you might see the Daikin error code 8a appear. That’s because it tells you that the boiler has gone into freeze protection mode. This is triggered when the flow temperature sensor shows a value of less than 1°c.

Prevention is better than cure for this one by avoiding the boiler being turned off in cold conditions or by switching on frost protection mode. It is possible that your Daikin thermostat isn’t working as it should, or there’s a faulty sensor causing an incorrect reading.

So, if the temperature is above freezing, you might be able to try a reset to see if that gets everything working again.

We also have a complete guide on the temperature your thermostat should be set at, which might also be a helpful read.

All Daikin Boiler Error Codes

Daikin Error Code	Fault
10-64	Faulty gas valve circuit error
10-65	Faulty gas valve current error
11-64	Error within ignition
11-65	An error within flame stabilisation
11-66	Loss of flame signal
11-67	Flame loss during operation
12-64	Deviation of ion control too great
12-65	An error within ignition scott actuators
12-66	Ion base value lower than the minimum limit
12-67	Ion base value exceeds the maximum limit
12-68	Ion base value different from previous
12-69	Offset adaptation reached the limit
13-64 / 13-65	Error with fan speed
16-64	Overheating of flue temperature signals
1J-64	Overheating of high limit thermostat
80-01	An error within the temperature sensor
81-01	Error with flow temperature sensor
81-65	Faulty hot water temperature sensor
8A-46	Freeze protection mode
8H-65	A steep rise within flow temperature
E1-64	Detection of flame before burner operates
E1-65	An error of internal SCOT system
E1-66	Error in calibration condition
E1-67	Calibration missing
E1-68	Ion base value exceeds the maximum limit
E1-69 / E1-70	Fault with parameter CRC
E1-71	Failure of EK lockout
E1-72	SCOT flame amplifier
E1-73	An error within the printed circuit board
H9-01	Fault with outside sensor
HC-01	Faulty hot water temperature sensor
HJ-08	System pressure too high
HJ-09	System pressure too low
HJ-10	Fault with water pressure sensor
J6-01	Overheating of flow temperature sensor
J6-20	Overheating return temperature sensor
J6-21	Higher return temperature than flow temperature.
JJ-64	Supply voltage below the low limit
U2-01	Supply voltage above the high limit
U4-65	Defective openTherm room thermostat
U4-66	Timeout of CAN-bus
U4-67	Remote reset supervision,
UA-64	Boiler chip card (BBC) blocked
UA-65	Updated needed for printed circuit board
UA-66	An issue with boiler chip card ID
UA-67	Missing boiler chip card

Daikin error and faults codes summary

A faulty boiler can be a complete nightmare so getting it working again is always a priority. Daikin fault codes are the first step in establishing what the problem is and helping you to decide if you can resolve the issue yourself or if you’ll need to call out an engineer. Be careful to make sure repairs aren’t more than what a new boiler cost.

If your looking at budget boilers and wanting to consider the issues that they may have, check out these other low cost boielrs that may be of interest and the issues that they have. here are the latest Keston error codes & Navien Error codes for you to browse.

All boilers do have a working lifespan. So, if you find that you have to call out the engineer, again and again, you might have got to the point where a replacement boiler is the best option. No more worries about whether the heating will work or if the children can have a hot bath!  We know though, that there so many different options that it can seem challenging to know where to begin.

This is where our fixed price quotation service comes in. Simply enter your requirements, and we’ll provide personalised boiler deals on some of the best combi boilers and system boilers. Suddenly a new boiler seems much more straightforward!