A Panasonic Aquarea error code is a letter and two digits on the remote controller display, such as H62 or F12, that tells you which part of the system has a problem. H-codes cover the indoor unit, the water circuit, sensors and communication. F-codes cover the outdoor unit and the refrigerant circuit.
Panasonic's user guide says a code can appear when something is wrong with the settings or with how the unit is running, and it tells owners to contact their installer. One rule matters more than the rest: never open the indoor or outdoor unit or touch wiring inside, as both carry mains voltage.
If a code keeps coming back after a reset, or you are not sure what it means, book an Aquarea repair with our engineers. If you own a different make, our heat pump error codes hub links to guides for other brands.
Is it safe to fix a Panasonic Aquarea heat pump fault yourself?
Only the basics are safe for a homeowner: reading the code, checking the power supply, clearing the outdoor unit and checking system pressure. Panasonic itself treats almost every code as installer work.
Do not remove covers or touch electrics inside the unit. Most F-codes relate to the outdoor unit or refrigerant circuit, and in the UK refrigerant work can only legally be done by an F-Gas certified engineer.
Think about your warranty too. Manufacturer warranties generally expect qualified installation and maintenance, so opening the unit yourself could cause problems with a claim later.
Please read first: this guide is here to help you understand what your Panasonic Aquarea heat pump is telling you. Every effort has been made to keep the information accurate, but manufacturers update their manuals and codes can differ between models and software versions, so always check the official Panasonic Aquarea manual for changes before acting on anything here. Do not attempt anything that could be dangerous, and avoid any work that could void your warranty. If in doubt, call a qualified heat pump engineer.
If your Panasonic Aquarea heat pump is not showing a code, or you want to rule out the basics first, our guide to common ASHP problems walks through the general checks and matches common faults to error codes across every major brand.
Which Panasonic Aquarea error codes can you check yourself?
A few Aquarea codes have a realistic, safe check you can make before calling anyone. The rest need an engineer.
| Code | What it means | Safe homeowner check | Stop and call an engineer if |
|---|---|---|---|
| H62 | Water flow too low | Check the isolation valves on the pipes under the unit are open and the pressure gauge reads normally | It returns after one Error Reset |
| H21 | Abnormal water pressure | Read the pressure gauge. If you have a filling loop and your manual allows it, top up to the marked level and look for drips | Pressure drops again, or you can see a leak |
| H42 | Low compression pressure in heating | Clear leaves, snow or debris from the outdoor coil and around the unit | It comes back with the unit clear |
| H98 | High pressure protection in heating | Check radiator valves are open, then reset once, as Panasonic advises | It repeats after that one reset |
| H70 | Back-up heater overload protection | Bleed radiators if you are used to doing it, as trapped air is a listed cause | It returns, or you smell burning |
| F15 | Outdoor fan motor locked | Look for anything jamming the fan guard from outside and clear it | The fan still will not turn |
| F41 | Power factor correction fault | After a power cut or spike, reset once | It comes back with a stable supply |
| H76 | Controller has lost contact with the indoor unit | Check the controller screen is lit, then try one Error Reset | The controller stays blank or the code returns |
| F32 | Controller thermostat abnormal | Compare the room temperature shown with a separate thermometer | The readings are far apart |
What are the most common Panasonic Aquarea heat pump error codes?
The Aquarea codes we are called out for most are water flow, pump, pressure and freeze protection faults, followed by sensors and communication. Panasonic's listed causes come first in each entry; anything marked general engineering knowledge is our own experience, not the manual.
H62: water flow fault
The unit has measured flow below its limit for 10 seconds (it ignores the first nine minutes after the compressor starts). Panasonic lists air in the system, closed isolation valves, a check valve fitted the wrong way, a leak or blockage, wiring, a faulty flow sensor and a faulty indoor PCB.
General engineering knowledge: a blocked strainer, sludge in the primary circuit, a weak pump and an undersized or throttled circuit are frequent underlying causes. Check the valves are open, reset once, and call us if H62 returns.
H20: water pump fault
The pump speed has been outside 1,000 to 6,000 rpm for five seconds. Panasonic lists debris, damaged pump wiring, a failed pump, a faulty indoor PCB and a rotor seized after a long standstill. General engineering knowledge: sludge and magnetite are usually behind both debris and seized rotors, which is where a heat pump powerflush can help.
H21: water pressure fault
Panasonic lists a faulty water pressure transducer or a water leak. General engineering knowledge: check the gauge first, because low pressure after a leak or a slow loss is the usual trigger. Our guide to a heat pump losing pressure covers where that water tends to go.
H42: low compression pressure in heating
The pipe sensor reads outside its range five minutes after the compressor starts. Panasonic lists a dirty outdoor coil, restricted airflow, a part-closed service valve, a faulty fan motor, low refrigerant, a blocked expansion valve or filter, a sensor fault or the outdoor PCB.
General engineering knowledge: a coil left iced after failed defrosting restricts airflow in the same way, so H42 often shows in a cold snap. See what to do about a frozen outside unit. Refrigerant checks need an F-Gas engineer.
H98 and F95: high pressure protection
H98 is high pressure protection in heating mode, and F95 is the same in cooling. Panasonic lists a faulty high pressure sensor, a pump fault or water leak, a blocked expansion valve or filter, too much refrigerant and the outdoor PCB. General engineering knowledge: poor water flow from air locks, scale or sludge raises head pressure, so rule out H62-type causes first and reset only once.
H99: indoor freeze protection
The indoor heat exchanger is close to freezing. Panasonic lists a faulty indoor heat exchanger or a refrigerant shortage. General engineering knowledge: very low water flow can let the plate heat exchanger get that cold, so air locks and sludge are worth checking. This is an F-Gas engineer visit.
A related code, H65, affects two-fan units during defrost. Panasonic links it to an external pump wired in series with the built-in pump, or a faulty flow sensor, pump or PCB.
H90 and H76: communication faults
H90 means the indoor and outdoor units have lost contact for over a minute after start-up. H76 means the indoor unit cannot talk to the control panel. Panasonic points to wiring, a disconnected or faulty controller and faulty PCBs, so beyond checking power, these need an engineer.
Sensor codes
Nineteen Aquarea codes are sensor faults, including H15, H23, H72, F36, F37 and F45. Panasonic lists a disconnected or faulty sensor, a poor connector or a faulty PCB, usually detected after five seconds. An engineer checks the sensor's resistance against its curve and replaces what has failed.
F14 to F25: refrigerant and drive faults
These include abnormal compressor speed (F14), compressor overheat (F20), inverter module overheat (F22) and a refrigerant cycle error (F24). They need an engineer, and anything touching the refrigerant needs an F-Gas engineer. They do not automatically mean compressor failure.
Which error code might you see in common situations?
What was happening when the code appeared usually points to the right one. Here are the Aquarea codes most linked to everyday situations.
| Scenario | Aquarea codes you may see | First check |
|---|---|---|
| Cold snap and iced outdoor unit | H42, H99, H65, F43 | Clear snow and ice from around the unit and let it defrost |
| Losing pressure or low pressure | H21, H62 | Read the pressure gauge and look for drips at valves and joints |
| Radiators lukewarm | H62, H75, H20 | Check isolation and radiator valves are open |
| No hot water | H72, H91 | Note the code and check the heating still works |
| After a power cut | F41, H95, H90 | Check the breaker, then do one Error Reset |
| Unit noisy or fan not spinning | F15, H42 | Look for anything blocking the fan from outside |
| After a service or filter clean | H62, H70, H76 | Confirm valves were reopened and the controller is lit |
If the system is dripping as well as showing H21, our guide to a heat pump leaking water explains which leaks are normal condensate and which are not.
How do you reset a Panasonic Aquarea heat pump?
You reset an Aquarea code with the Error Reset function in the remote controller's Quick Menu. The H-series user guide sets it out like this:
- Turn off all units at the controller.
- Open the Quick Menu.
- Press and hold the button your user guide names for 5 seconds.
- Select Reset. The screen switches off after about 3 seconds.
If the code comes straight back, the fault is still there and needs an engineer. Older Aquarea generations may differ, so check the guide for your model.
Resist the urge to keep resetting. Each restart puts the compressor through another start under the same fault, and with flow or pressure codes that can turn a minor problem into a costly one.
Panasonic Aquarea error code list
This list is based on the Aquarea WH-ADC H-series (Generation H) documents. Older Aquarea models may use fewer or different codes, so check your own manual if a code is missing or reads differently.
| Code | Meaning | Who should fix |
|---|---|---|
| H00 | No fault detected | No action |
| H12, H38 | Indoor and outdoor units do not match (capacity or brand) | Engineer |
| H15 | Outdoor compressor temperature sensor | Engineer |
| H20 | Water pump fault | Engineer |
| H21 | Water pressure fault (listed in Panasonic's Pro Club document, not the user guide) | Homeowner check, then engineer |
| H23 | Indoor refrigerant liquid temperature sensor | Engineer |
| H27 | Service valve error (cooling) | F-Gas engineer |
| H28, H31, H36 | Solar, swimming pool or buffer tank sensor | Engineer |
| H42 | Low compression pressure | Homeowner check, then F-Gas engineer |
| H43, H44 | Zone 1 or zone 2 water temperature sensor | Engineer |
| H62 | Water flow fault | Homeowner check, then engineer |
| H63 | Low pressure sensor | F-Gas engineer |
| H64 | High pressure sensor or switch | F-Gas engineer |
| H65 | Defrost water circulation fault | Engineer |
| H67, H68 | External thermistor 1 or 2 | Engineer |
| H70 | Back-up heater overload protection | Homeowner check, then engineer |
| H72 | Tank sensor fault | Engineer |
| H74 | Communication with expansion board | Engineer |
| H75 | Low water temperature control | Engineer |
| H76 | Indoor unit to controller communication | Homeowner check, then engineer |
| H90 | Indoor to outdoor communication | Engineer |
| H91 | Tank heater overload protection | Engineer |
| H95 | Wrong connection or voltage | Engineer |
| H98 | High pressure protection, heating | Homeowner check, then F-Gas engineer |
| H99 | Indoor heat exchanger freeze protection | F-Gas engineer |
| F12, F27 | High pressure switch tripped or faulty | F-Gas engineer |
| F14 | Abnormal compressor speed | F-Gas engineer |
| F15 | Outdoor fan motor locked | Homeowner check, then engineer |
| F16 | Total running current protection | F-Gas engineer |
| F20 | Compressor overheat | F-Gas engineer |
| F22 | Inverter module overheat | Engineer |
| F23 | DC peak, outdoor | Engineer |
| F24 | Refrigerant cycle error | F-Gas engineer |
| F25 | Cool or heat cycle error (4-way valve) | Engineer |
| F29 | Low discharge superheat | F-Gas engineer |
| F30, F37, F45 | Water outlet 2, inlet or outlet sensor | Engineer |
| F32 | Controller thermostat abnormal | Homeowner check, then engineer |
| F36, F40, F42, F43 | Outdoor ambient, discharge, heat exchanger or defrost sensor | Engineer |
| F41 | Power factor correction fault | Homeowner check, then engineer |
| F46 | Current transformer disconnected | F-Gas engineer |
| F48, F49 | Evaporator outlet or bypass outlet sensor | Engineer |
| F95 | High pressure protection, cooling | F-Gas engineer |
Where can you find the official Panasonic Aquarea manual?
Panasonic's UK Documents & Support page holds the operating manuals for owners, and its Pro Club site hosts the installer guides and self-diagnosis document this guide draws on. The self-diagnosis document is in Polish, but its code tables are easy to follow.
- Panasonic Heating & Cooling UK: Documents & Support (operating manuals)
- Panasonic Pro Club: Aquarea self-diagnosis guide, Generations H, J, K and L (2023 PDF, Polish)
- Panasonic Pro Club: Aquarea Installation Guide 1.3, Monobloc H and J Generation (UK PDF)
Need help with a Panasonic Aquarea heat pump fault?
We repair Panasonic Aquarea heat pumps across the UK, from monobloc and bi-bloc units to all-in-one systems. Our engineers are F-Gas certified, we are MCS accredited, and our repairs carry a 12-month guarantee.
Every visit starts with fault diagnosis: we read the code, test sensors and flow, and check the refrigerant circuit where needed, so the repair targets the real cause. We aim for same-day visits where we can, and our emergency heat pump repair service is there if you are left without heat or hot water.
Many Aquarea codes, H62, H20 and H42 among them, trace back to sludge, blocked strainers or a dirty coil. Annual heat pump servicing catches those early, and our cover plans bundle servicing with repair cover. More on the brand is on our Panasonic heat pump page.
Call 0333 041 5130 or get in touch online to book.
Frequently asked questions
Does an Aquarea error code void the warranty?
No, a code is the heat pump protecting itself and does not affect your cover by itself. Warranty trouble usually comes from ignoring a fault for weeks or from unqualified work inside the unit. Our Panasonic Aquarea review covers what to keep in mind when you own one.
What does H00 mean on an Aquarea?
H00 means no abnormality has been detected. You might see it when checking the error display, and it needs no action. If the heating still is not working with H00 showing, the cause lies outside the unit's self-diagnosis, so book a check.
Why would I see F25 or F95 if I only use heating?
Both are cooling-mode codes, and Panasonic locks cooling unless an authorised installer unlocks it. Seeing one on a heating-only system is unusual, so note it down and ask an engineer to look at the settings and the 4-way valve.
Can I see Aquarea error codes on my phone?
If your system is linked to Panasonic's online control service, codes may show remotely as well as on the controller. Not every installation is connected, so check with your installer. The remote view does not replace a visit when the same code keeps returning.
Does the Aquarea controller keep an error history?
The user guide does not explain how to view past codes, so do not rely on the controller to remember. Write down the code, the date and time, and what the system was doing. That note makes our diagnosis quicker.
