Baxi heat pump faults: 35 codes and what you can check

A warning on a Baxi heat pump may indicate an incorrect temperature reading, insufficient water circulation, an external lockout or an outdoor unit fault. The code must be read alongside the model: it does not, on its own, identify a part that needs replacing. If H02.07, H02.23 or E02.24 appears, you can check the displayed pressure and observe the equipment without dismantling it; internal checks require a qualified technician.

If you have a problem with your heat pump, you can use our free error code finder. It helps you identify faults and find straightforward, effective guidance on resolving them.

The model determines what each warning means

The available reference material brings together codes used in the Platinum BC iPlus family and others specifically identified for Platinum BC iR32. Although they share a manufacturer and may look similar on the display, they are not a universal catalogue for every Baxi heat pump. The interpretation must be checked against the installed unit’s manual, particularly where the range, controller or system configuration differs.

The table brings together 35 distinct identifiers found in the reference material. Four are explicitly identified for Platinum BC iR32: H06.28, H06.06, H06.07 and H06.36. That distinction matters: a communication fault and a refrigerant pressure protection event require different investigations, even though both can stop the heating. A matching code does not replace a compatibility check against the specific equipment.

Before acknowledging or clearing a message, it helps to take a photograph showing the complete code, including letters, dots and zeros. Note the model too, and whether the problem affects heating, cooling or domestic hot water, abbreviated as DHW. With those details, diagnosis starts from verifiable information, rather than an approximate memory of the warning or an assumed equivalent from another brand.

The 35 codes and the faults they help locate

The description in each row explains the condition detected by the controller, while the cause sets out the possibilities associated with it in the reference material. A likely cause is not a confirmed fault: a sensor can report an abnormal reading because of the sensor itself, its connection or the associated circuit. The action column therefore distinguishes user observations from technical work.

Pressure and circulation codes deserve particular attention because they can be confused with each other. Codes involving sensors, configuration, circuit boards or communication require internal components to be checked. In all these cases, there is no need to open the appliance to identify the message, and doing so does not provide a safe user check. The table keeps the faults separate to avoid applying the same remedy to different problems.

Pressure and flow are not corrected in the same way

H02.07 and A02.06 point towards water pressure in the heating circuit. H00.40, by contrast, points to the pressure sensor’s measurement circuit. You can read the gauge or the value shown by the controller, but an abnormal reading does not prove there is a water leak. A measurement problem is another possibility, and recognising the difference prevents unnecessary topping up or inappropriate work.

H02.23, A02.22 and E02.24 relate to circulation. Pressure describes the circuit’s pressurised state; flow describes how much water is moving through it. A system can display apparently suitable pressure yet still fail to circulate enough water because of dirt, air, a stopped pump or incorrect measurement. In other words, having pressure does not guarantee having flow, just as a full pipe does not guarantee that water is moving along it.

The reference material does not provide a filling pressure or minimum flow rate that applies to every installation covered here. Those values depend on the model and hydraulic design and must be checked in the relevant documentation. Home checks are limited to reading indicators and observing visible leaks. Do not open hydraulic filters, air vents or filling valves to try possible fixes: they can contain hot, pressurised water and require a controlled intervention.

If E02.24 returns after a reset authorised by the manual, do not keep trying to restart the unit. The shutdown protects the equipment against insufficient circulation, and clearing the warning does not restore water movement. If DHW is also affected, using hot water alone should not be assumed safe: both services may share installation components affected by the same fault.

Sensors report a reading, not always the actual temperature

Many H00 messages, along with E00.00 and E00.01, describe measurement faults. A sensor converts temperature into a signal that the controller can interpret. When an open circuit or short circuit occurs, that signal becomes unreliable. An out-of-range value does not necessarily mean an extreme temperature in the water or outdoor air.

The sensor’s location helps explain the symptom. The flow sensor measures water leaving for the heating system; the return sensor monitors water coming back. Cylinder sensors support DHW control, while the outdoor sensor provides information about ambient conditions. They are not interchangeable simply because they measure temperature, and the code is not a reason to buy a generic sensor without checking the model and diagnosis.

It also matters whether a sensor is not detected or has an abnormal electrical reading. H00.34 means the controller expected to find an outdoor sensor but could not locate it; H00.32 and H00.33 describe conditions in its measurement circuit. That distinction can direct a technician towards installation, configuration or connection issues. For the user, the boundary comes before accessing the wiring, even when the component looks small or easy to replace.

Outdoor unit faults and lockouts need context

H06.01 identifies an outdoor unit fault, but does not, by itself, specify which component has failed. On Platinum BC iR32, H06.28 narrows the issue to lost communication, while H06.36 concerns the fan motor. From a safe position, you can observe whether an object is resting against the grille or whether obvious surface dirt is present. Do not insert tools or hands through the guards, even if the fan appears to have stopped.

H06.06 and H06.07 on that range concern high and low refrigerant circuit pressure. They do not describe the water pressure shown on the heating gauge. This distinction prevents a particularly inappropriate response: adding water does not correct a refrigerant circuit fault. Nor does a low-pressure alarm, without further testing, confirm a refrigerant shortage or a need for recharging.

BL-related messages represent a different situation: the controller receives a lockout condition through an input provided for that purpose. H02.09 describes a partial lockout, H02.10 a total lockout and E02.13 an external lockout request. A connected device may need investigation rather than the heat pump needing replacement. Never try to bypass the lockout by bridging contacts, because that would remove a signal whose purpose has not yet been established.

A restart must not erase the installation settings

A user restart and a factory reset are not equivalent. The former should only follow the procedure allowed by the manual; the latter can remove settings needed for the outdoor unit, zones and accessories to work correctly. With H02.02 or H02.03, CN1 and CN2 must match the installed equipment, not values copied from a similar installation.

H02.04 is particularly easy to misinterpret. The reference material describes restoring settings and, if the problem persists, assessing the main board. That does not make board replacement the first step or a factory reset a harmless home test. With H02.05, the focus is on agreement between CSU, CU and software. Configuration is part of technical diagnosis, not a sequence of trial-and-error checks.

H02.36 and H02.37 indicate lost communication with additional boards, while A02.55 concerns recognition of the serial number. Mention whether the warning appeared after maintenance, a component replacement or a system modification. That timing does not prove who or what caused the fault, but it can prevent replacement of working components when the actual problem is their identification or compatibility.

H02.60 has a different meaning: the selected function is unavailable for that zone. It is reasonable to check which zone is selected on the controller and which uses the manual permits. There is no need to change installer settings to try different combinations. If the function used to be available and has disappeared, keep that information for the inspection, rather than attempting to rebuild the configuration yourself.

An inspection starts with observations, not dismantling

Useful checks are those that do not alter the installation. You can read the pressure, check the selected zone, look for water marks and observe the clearance around the outdoor unit from outside. Cleaning should be limited to accessible surfaces and tasks authorised by the manual. A hydraulic filter is not a removable household filter: opening its housing can release hot, pressurised water.

Before any permitted reset, record the code and the circumstances in which it appeared. It matters whether it occurred during a DHW demand, when heating started or after a modification. If the message returns, the next step is diagnosis, not repeated restart attempts. If water is reaching electrical parts, there is a burning smell or unusually loud abnormal noise, stop using the equipment and avoid touching it; inspection requires qualified personnel.

If contractual cover or an applicable warranty remains in place, checking its terms before authorising work can prevent unnecessary decisions. Opening the equipment does not allow safe diagnosis of sensors, boards or refrigerant issues, and interference can complicate a later assessment. Preserving the equipment’s condition and the warning record is more useful than dismantling it to photograph a supposedly faulty part.

The cost depends on the cause, not the letters on the screen

The available reference material provides no verifiable repair price associated with these codes. Applying a commercial subscription advertised for boilers to a heat pump would also be inappropriate. The same message may lead to a configuration correction, connection checks or component repairs, and the code cannot establish a repair price without knowing the underlying cause and model.

Before accepting a repair, distinguish the diagnostic charge from the proposed work and check whether travel, labour and materials are included. Do not assume the call-out charge will be deducted later. When deciding between repair and replacement, consider age, overall condition, part availability and the extent of the damage. A single warning does not justify replacing the whole system, just as an older unit does not make every repair worthwhile.

The soundest decision comes once the message has been linked to a verified cause and a specific intervention. Until then, the table helps locate the problem and define what can be observed without risk. Baxi heat pump fault messages are a diagnostic tool, not an instruction to replace parts: reading them against the correct model prevents confusion between a protective shutdown, a measurement fault and an actual component failure.