Heat pumps · Mallorca
Daikin Altherma
error codes:
what each one means
These are the 29 codes of the outdoor unit —the machine outside—, with what each one means and, above all, who should look at it: 9 you can check yourself without opening anything, 14 that need a technician and 6 that should not be left running.
We are Joaquín and Juan. We install and maintain heat pumps all over Mallorca as an authorised thermal installation and maintenance company (RITE) and, being also an authorised low-voltage installation company, we look at the unit and at the board feeding it.
Daikin Altherma 3 R · Image: Daikin
Before the code: most of these are not a fault
Worth knowing first, because it saves a scare: most of these codes are not a breakdown. They are the machine protecting itself. It has seen something it does not like —pressure, temperature, voltage— and it stops before it breaks. That is why many of them clear on their own and come back later: the code goes away, the cause does not.
Where to read the code: on the display of the indoor unit controller. It looks like this: two characters, a hyphen and two digits — E3-00, J6-07, U2-00. Write it down in full, including the last two digits: J6-00 and J6-07 are not the same line in the guide.
One code, one machine. This is the Daikin Altherma. On other brands, and on other Daikin ranges, the same characters can mean something else. The Altherma has 82 codes in total: this page covers the 29 of the outdoor unit, and the indoor ones will be added right here.
The same 29, explained on video
Two videos, split the same way as this page: the first one covers pressure, refrigerant, compressor and fan; the second one the electronics, the power supply, the inverter and the sensors. What is said there is exactly what is written below.
Daikin Altherma Error Codes: Outdoor Unit (1 of 2)
Daikin Altherma Error Codes: Outdoor Unit (2 of 2)
The 29 codes, by family
For each one you get the name Daikin's guide gives it and, below, what it means in practice and who should look at it.
Pressure and refrigerant
The machine has stopped because of pressure or because refrigerant is missing. This is where the cause is most often outside the unit.
E3-00 OU: Actuation of high pressure switch (HPS) You can check this
The unit has stopped because the refrigerant pressure went sky high. In summer, and here in Mallorca, the number one cause is simple: the outdoor unit cannot get rid of the heat. Check that it is not covered, that there are no leaves or fluff in the grille, that nothing has been placed in front of it and that it is not baking in full sun all afternoon. You can see that yourself in two minutes.
FA-00 OU: Abnormal high pressure, actuation of HPS You can check this
Same high pressure problem, just logged differently by the unit. Same check: grille clear and clean. If it is clear and the code comes back, it is not dirt any more.
H3-00 OU: Malfunction of high pressure switch (HPS) That is our job
Here it is the pressure switch itself that has failed, the switch that watches the pressure. This cannot be checked from outside: it is a part, and it is our job.
F6-00 OU: Abnormal high pressure in cooling You can check this
Abnormally high pressure while running in cooling. If your unit also does cooling in summer, check the usual — grille and ventilation — and call us.
A5-00 OU: High pressure peak cut / freeze protection problem You can check this
A cut-out on a high pressure peak, or a problem with freeze protection. It can show up in very cold weather or with a dirty coil. Checking the grille costs nothing; the rest is our job.
U0-00 OU: Shortage of refrigerant Do not leave it running
The unit is short of refrigerant. And be careful with this one: refrigerant is not consumed. If some is missing, it has leaked out somewhere. There is nothing for you to check here. And be wary of anyone offering to just top up the gas without finding the leak: in a few months you are back where you started, and paying again.
JA-00 OU: Malfunction of high pressure sensor Do not leave it running
A fault in the high pressure sensor: the unit does not trust what it is reading. Ours. And it is one to deal with, because without that sensor the unit protects itself by stopping.
The compressor
The compressor is the heart of the machine and its most expensive part. None of these can be checked from outside.
E5-00 OU: Overheat of inverter compressor motor Do not leave it running
The compressor motor has overheated, and the compressor is the heart of the unit. This is our job. Do not leave it running to see if it settles, because the compressor is the most expensive part in there.
E6-00 OU: Compressor startup defect That is our job
The compressor is not starting as it should. Ours. It can be electrical or mechanical, and it gets measured, not guessed.
H6-00 OU: Malfunction of position detection sensor That is our job
A fault in the sensor that tells the unit what position the motor is in. Electronics. Ours.
H8-00 OU: Malfunction of compressor input (CT) system That is our job
A fault in the system that measures the compressor input current. Ours, and it is measured with a clamp meter.
F3-00 OU: Malfunction of discharge pipe temperature Do not leave it running
The discharge pipe temperature has gone out of range. It usually goes hand in hand with low refrigerant or poor circulation. Ours. This is one not to leave alone: running like that, the compressor suffers.
Fan and heating/cooling changeover
The fan of the outdoor unit and the valve that switches between heating and cooling.
E7-00 OU: Malfunction of outdoor unit fan motor You can check this
A fault in the outdoor unit fan motor. What you can check: that nothing is jamming the blades — a bag, a branch — and that the blades are not broken. With the unit switched off, of course. The rest is ours.
EA-00 OU: Cool/heat switchover problem That is our job
A problem switching between cooling and heating. It is the four-way valve or its control. Ours.
The power reaching the unit
The power reaching the machine from the house board. Part of this one is yours.
E8-00 OU: Power input overvoltage You can check this
The unit is getting more voltage than it can take. This one is partly yours, because the problem is in the house supply, not inside the machine. Notice whether it happens at the same time as something else resetting, whether you have solar panels, or whether it is always at the same time of day. If it keeps happening the electrical installation needs measuring, and we do that too: we are registered electrical installers, not only refrigeration.
H0-00 OU: Voltage/current sensor problem That is our job
The sensor that measures voltage and current inside the machine has failed. It is not that power is missing: the machine does not trust its own reading. Our job. It is measured with a clamp meter and compared against what the machine reports.
U2-00 OU: Defect of power supply voltage You can check this
The voltage reaching the machine is not what it should be: low, unstable or badly balanced. What you can check, and it is quick: whether a breaker or the RCD in your consumer unit has tripped, and whether you notice the lights dip when something big starts up. It also shows up when the cable feeding the machine is too thin for the distance it runs. That part gets measured.
Electronics and inverter
The board, the inverter and the heat they generate themselves. Two of these depend on where the unit was installed.
E1-00 OU: PCB defect That is our job
The electronic board of the outdoor unit has failed, and that board is the brain of the machine. There is nothing for you to check here, but there is something worth telling us: if there was a storm, a power cut or a dip just before, say so, because boards very often go that way. And one thing from our side: the board is expensive, so we make sure it really is the board before replacing it. We do not swap parts and hope.
L5-00 OU: Inverter instantaneous overcurrent (DC) Do not leave it running
The inverter, which is the electronics that drive the compressor, saw a current spike and cut out instantly so it would not burn out. Entirely ours, and one of the serious ones: it can be the inverter itself or the compressor. Do not leave it restarting over and over to see if it catches, because every attempt is another spike.
L3-00 OU: Electrical box temperature rise problem You can check this
The electrical box of the outdoor unit has got too hot. There is real work for you here: check that the machine is not boxed in without air, that it is not in full sun all afternoon, and that the cover is on and properly closed. If it is in a small cupboard, a light well or behind an unventilated screen, that is the reason, and no spare part will fix it.
L4-00 OU: Malfunction of inverter radiating fin temperature rise You can check this
The inverter heat sink, the fins that cool that electronics, has gone over temperature. Same chapter as the previous one: a ventilated spot and shade. What you cannot see is that the heat sink fills up with dust inside; we clean that when we open it.
P4-00 OU: Malfunction of radiating fin temperature sensor That is our job
Nothing has overheated here: what has failed is the sensor that measures that temperature. Ours. It is a small part, and far cheaper than what it protects.
LC-00 Malfunction in communication system of outdoor unit That is our job
The boards inside the outdoor unit have stopped understanding each other. Ours. It is usually a connection, a cable or a board, and they get ruled out in order. If the unit is new and it has done this from day one, tell us: it changes quite a lot where we start looking.
U7-00 OU: Transmission malfunction between main CPU- INV CPU That is our job
Another communication breakdown, like the previous one, but specifically between the main brain and the inverter one. Ours. Same route: connections first, board afterwards.
Sensors
Sensors are what tell the machine what is going on. With one faulty, it works blind.
H9-00 OU: Malfunction of outdoor air thermistor That is our job
The sensor that tells the machine the outdoor temperature has failed. Without that reading it works blind and uses more energy. You cannot see it from outside, it sits inside the casing. It is ours, and one of the cheap ones to put right.
J3-00 OU: Malfunction of discharge pipe thermistor Do not leave it running
The sensor watching the temperature of the pipe where the hot gas leaves the compressor has failed. Ours. And be careful with this one: that sensor is exactly what protects the compressor from cooking itself, so it is not one to leave until next month.
J6-00 OU: Malfunction of heat exchanger thermistor That is our job
The sensor measuring the temperature of the heat exchanger has failed, and that is the big coil in the outdoor unit. Ours. With that sensor faulty the machine does not know when to defrost, and in winter you notice it: it stops giving heat.
J6-07 OU: Malfunction of heat exchanger thermistor That is our job
This is the same heat exchanger sensor warning with a different suffix. In the Daikin guide both carry exactly the same description. We list it separately because if your display shows J6 dash zero seven and you only find J6 dash zero zero, you are left wondering. For you it means the same thing and it is fixed the same way: it is ours.
When the pair does not match
When the indoor and outdoor units were not made to work together.
UA-00 Indoor unit, outdoor unit matching problem That is our job
The indoor unit and the outdoor unit do not match: the machine is saying that pair was not made to work together. This one deserves a pause. It shows up mostly when one of the two has been swapped for something that does not correspond, or when it was set up wrong at commissioning. If a unit has just been replaced and this started, it is no coincidence. Write down the references from both rating plates, the one outside and the one inside, and send them to us: with that we can tell you whether the pair is right.
The 9 you can check yourself, without opening anything
None of these asks you to open the machine or touch any wiring. Almost all come down to the same two checks: that the machine can breathe —grille clear and clean, nothing in front of it, shade in the afternoon and the cover on and properly closed— and that nothing is jamming the fan blades, with the machine switched off. The two voltage ones, E8-00 and U2-00, are not about the machine but about the power in the house: check whether a breaker or the RCD in your board has tripped.
Have a look and call us with what you found. It tells us where to start and saves you the wait.
- E3-00 · OU: Actuation of high pressure switch (HPS)
- FA-00 · OU: Abnormal high pressure, actuation of HPS
- F6-00 · OU: Abnormal high pressure in cooling
- A5-00 · OU: High pressure peak cut / freeze protection problem
- E7-00 · OU: Malfunction of outdoor unit fan motor
- E8-00 · OU: Power input overvoltage
- U2-00 · OU: Defect of power supply voltage
- L3-00 · OU: Electrical box temperature rise problem
- L4-00 · OU: Malfunction of inverter radiating fin temperature rise
The 6 that should not be left running
These are not for "I will look at it later". Restarting again and again to see if it holds is expensive: on several of them every attempt is another hit on the compressor, the most expensive part of the unit. Write down the code and the time, or take a photo of the display, and call us with that.
Daikin heat pumps in Mallorca
We cover the whole island: Palma, Llucmajor, Campos, Santanyí, Felanitx, Manacor, Calvià, Andratx, Marratxí, Porto Cristo and Cala d'Or, among others. We install, certify and maintain heat pumps of every brand, Daikin being one of them.
The outdoor unit of a heat pump lives outside all year round, and here that shows: full sun in summer, salt air near the coast and dust. That is why the first check on this page is always the same —that the machine can breathe— and why it is worth looking at it before the summer, not in August with a full house.
A heat pump is a thermal installation: it is governed by the Spanish RITE regulation; it must be installed and certified by an authorised thermal installation company and maintained by an authorised maintenance company (art. 26). JSL is authorised for both (and, separately, is listed in the REA under no. 04/01/0010572). We also handle the design, the permits, the certification and the grant paperwork.
Frequently asked questions
Frequently asked questions about Daikin Altherma error codes
Where do I see the error code of my Daikin Altherma?
On the display of the indoor unit controller. The code looks like this: two characters, a hyphen and two digits, such as E3-00, U2-00 or J6-07. Write it down in full, including the last two digits, because J6-00 and J6-07 are two different lines in Daikin's guide. The Altherma handles 82 codes in total; this page covers the 29 of the outdoor unit, the machine that sits outside. In Mallorca that unit is usually on a roof terrace or in a courtyard, but the code is always read indoors, on the Daikin Altherma indoor controller.
My heat pump has stopped and shows E3-00. What can I check myself?
E3-00 means the refrigerant pressure is too high, and in summer the number one cause is that the outdoor unit cannot get rid of the heat. Check that it is not covered, that the grille has no leaves or fluff, that nothing has been placed in front of it and that it is not baking in full sun all afternoon. In Mallorca these units are often installed on a roof terrace or in an enclosed courtyard, and that is where they overheat. It takes two minutes and you do not need to open anything; if the grille is clear and the code comes back, it is no longer dirt.
I have been told to top up the refrigerant. Does it get used up?
No. The refrigerant runs in a sealed circuit and is not consumed. If code U0-00 says it is low, it has leaked somewhere and what needs finding is the leak: topping up without finding it leaves you in the same place a few months later, paying twice. On top of that, only a company holding the fluorinated gas certification —which is separate from RITE— may work on a refrigerant circuit. JSL holds both and works across Mallorca.
How often does a heat pump need servicing?
The Spanish RITE regulation sets it out in IT.3, table 3.1, and it depends on the power: in a home, up to 12 kW the check is at least every 4 years, and between 12 and 70 kW at least every 2 years. Note the wording of the regulation: it says «at least». In Mallorca, with the outdoor unit exposed all twelve months to sun, dust and salt air, we recommend looking at it once a year and before the summer, which is when it will work hardest.
A code came up. Can I reset it and keep using the machine?
It depends on the code. Six on this list should not be treated that way: E5-00, F3-00, JA-00, U0-00, L5-00 and J3-00. On those, every restart to see if it holds is another hit on the compressor, the most expensive part of the unit, or another current spike for the inverter. Write down the code and the time, take a photo of the display and call us with that before trying again: we service Daikin heat pumps across Mallorca.
Can any installer fit a heat pump?
No. A heat pump is a thermal installation governed by the Spanish RITE regulation: it must be installed and certified by an authorised thermal installation company and maintained by an authorised maintenance company (art. 26). JSL is authorised for both (and, separately, is listed in the REA under no. 04/01/0010572). If the refrigerant circuit has to be opened, the fluorinated gas certification is needed as well, and the electrical board the machine hangs from is low voltage, REBT, which is yet another authorisation. We hold all three, which is why in Mallorca we look at the machine and at the board feeding it, not just one of the two.
Do you work on Daikin heat pumps across Mallorca?
Yes. We install, certify, maintain and repair heat pumps all over the island: Palma, Llucmajor, Campos, Santanyí, Felanitx, Manacor, Calvià, Andratx, Marratxí, Porto Cristo, Cala d'Or and the rest of the municipalities. We work with every brand, Daikin included, and we also handle the design, the permits, the certification and the grant paperwork.
Is your heat pump showing a code?
Tell us the code exactly as it appears on the display and what the machine was doing, and we will tell you what it needs.
Where this information comes from
The name of each code is the one in Daikin's installer guide, translated by JSL. The code itself is never translated.
The explanation is ours: it is the same text we say in the two videos above, word for word, so that page and video do not contradict each other. We do not copy the manual and we do not publish procedures an owner should not carry out.
The grouping into families and the "who looks at it" column are JSL's own judgement, not the manufacturer's: their guide is written for an installer. Here we only publish what an owner can check safely.
Of the 82 codes of the Altherma, these are the 29 of the outdoor unit. The indoor ones will be added on this same page once they are written to the same standard: we do not publish made-up content.
Daikin is a trademark of its owner. JSL Mallorca is not its official service centre: we are an installation company that fits and repairs this equipment. This guide is technical information, not manufacturer documentation.