What is the Toshiba HWS-802XWHT6-E?

The Toshiba HWS-802XWHT6-E is an 8kW split air-source heat pump featuring a 3-phase backup heater and a COP of 4.08 at A7/W35. It is designed for domestic heating and hot water applications, providing flow temperatures up to 55°C even in outdoor temperatures as low as -20°C.

How do I register a Toshiba HWS-802XWHT6-E with BoilerTag?

Scan the QR code on the BoilerTag sticker after installation to begin the process. Confirm the model details, which will pre-fill from the catalogue, and record the installation date and your Gas Safe or F-Gas number. Every future service log becomes a permanent, publicly viewable record of the appliance's history. The first 12 BoilerTag stickers are free for engineers. Order free BoilerTag stickers from the engineer dashboard.

What is the COP of the Toshiba HWS-802XWHT6-E?

The Coefficient of Performance (COP) is 4.08 when measured at an outdoor air temperature of 7°C and a water flow temperature of 35°C. This indicates that for every 1kW of electricity consumed, the unit delivers 4.08kW of heat energy. Efficiency will vary based on the flow temperature required by the emitters and the prevailing outdoor conditions.

What refrigerant does the Toshiba HWS-802XWHT6-E use?

This model uses R410A refrigerant with a factory charge of 1.8kg. R410A is a hydrofluorocarbon (HFC) blend commonly used in split systems of this generation. Because it is a fluorinated greenhouse gas, all installation and maintenance work on the refrigerant circuit must be performed by an F-Gas certified engineer.

What does fault code A01 mean on a Toshiba HWS-802XWHT6-E?

Fault code A01 indicates a pump or water flow quantity error. This is triggered if the TC sensor exceeds 63°C or the flow switch fails to detect a signal for two minutes after the pump starts. Engineers should check for air locks, closed valves, a blocked strainer, or a disconnected flow switch connector.

What does fault code P03 mean on a Toshiba HWS-802XWHT6-E?

Fault code P03 signifies an outlet temperature error, occurring when the discharge temperature (TD) exceeds 111°C. Likely causes include a refrigerant gas leak, a defective Pulse Motor Valve (PMV), or a faulty TD sensor. Engineers should perform a leak test and verify the resistance of the discharge temperature sensor.

What are the dimensions of the Toshiba HWS-802XWHT6-E outdoor unit?

The outdoor unit (HWS-802H-E) measures 890mm in height, 900mm in width, and 320mm in depth. It weighs 63kg and requires specific clearances for optimal performance: 300mm at the sides, 600mm at the front, and 150mm behind the unit. These clearances ensure sufficient airflow across the heat exchanger.

Which hot water cylinders are compatible with the HWS-802XWHT6-E?

This hydro unit is compatible with Toshiba ESTIA cylinders, specifically models HWS-1501CSHM3-E (150L), HWS-2101CSHM3-E (210L), and HWS-3001CSHM3-E (300L). The system uses a dedicated TTW sensor to monitor cylinder temperature and manage the DHW reheat cycle via the internal 3-way valve.

Is the Toshiba HWS-802XWHT6-E a monobloc or split system?

It is a split system consisting of an outdoor heat pump unit and an indoor hydro unit connected by refrigerant piping. Unlike monobloc systems where all components are outdoors, the split configuration houses the heat exchanger and backup heater indoors, reducing the risk of external pipework freezing during power outages.

What is the minimum operating temperature for the HWS-802XWHT6-E?

The system is rated to operate in outdoor ambient temperatures as low as -20°C. At these lower temperatures, the heating capacity will reduce, and the internal 3-phase backup heater may be required to supplement the heat pump output to meet the building's heat loss.

What does fault code A01 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Pump or flowing quantity error Likely causes: Almost no or little water flow; Not enough vent air; Dirt clogging in the water piping system; Water piping is too long; Disconnection of the flow switch connector. Check water flow, vent air, clean strainer, check flow switch connection and operation.

What does fault code A02 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Temperature increase error (heating) Likely causes: Defective TWI, TWO, or THO sensors; Defect of the backup heater (automatic reset thermostat); Hot water from boiler or other circuits entering. Check sensors, check backup heater operation, correct water circuit if necessary.

What does fault code A03 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Temperature increase error (hot water supply) Likely causes: Defective TTW sensor; Defective hot water cylinder thermal cut-out. Check TTW sensor and hot water cylinder thermal cut-out.

What does fault code A04 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Antifreeze operation error Likely causes: Little water flow; Dirt clogging; Heater power circuit failure; Defective sensors (TWI, TWO, TC). Check water flow, heater power supply, and sensor characteristics.

What does fault code A05 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Piping antifreeze operation error Likely causes: Heater power circuit failure; Defective sensors; Disconnection of the backup heater. Check heater power circuit and backup heater connection.

What does fault code A07 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Pressure switch operation Likely causes: Little water flow; Defect of the flow switch; Defect in the pressure switch. Check water flow, flow switch, and pressure switch.

What does fault code A08 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Low pressure sensor operation error Likely causes: Little water flow; Defect of the flow switch; Prolonged defrosting; Defect in the low pressure sensor. Check water flow and low pressure sensor.

What does fault code A09 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Overheat protection operation Likely causes: No water (heating without water); No water flow; Defect of the flow switch; Defect of the backup heater. Check water level, flow switch, and backup heater thermostat.

What does fault code A11 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Operation of the release protection Likely causes: Almost no water flow; Defect of the flow switch; Defective TWO sensor. Check water flow and TWO sensor.

What does fault code A12 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Heating or Hot water supply heater failure Likely causes: Large heating load; Heater power circuit failure; Defective backup or cylinder heater. Check heater power circuit and heater elements.

What does fault code E03 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Communication error (Hydro - Remote) Likely causes: Remote control connection failure; Defective remote control. Check remote control wiring and unit.

What does fault code E04 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

Communication error (Hydro - Outdoor) Likely causes: Miswiring of crossover cables; Serial circuit failure. Check serial circuit and interconnecting wiring.

What does fault code F03 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TC sensor error Likely causes: Defective TC sensor; Loose connection. Check resistance and connection of TC sensor.

What does fault code F10 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TWI sensor error Likely causes: Defective TWI sensor; Loose connection. Check resistance and connection of TWI sensor.

What does fault code F11 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TWO sensor error Likely causes: Defective TWO sensor; Loose connection. Check resistance and connection of TWO sensor.

What does fault code F14 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TTW sensor error Likely causes: Defective TTW sensor; Loose connection. Check resistance and connection of TTW sensor.

What does fault code F17 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TFI sensor error Likely causes: Defective TFI sensor; Loose connection. Check resistance and connection of TFI sensor.

What does fault code F18 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

THO sensor error Likely causes: Defective THO sensor; Loose connection. Check resistance and connection of THO sensor.

What does fault code F19 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

THO sensor detach failure Likely causes: THO sensor disconnected from pipe. Check THO sensor attachment to pipe.

What does fault code F20 mean on the Toshiba HWS-802XWHT6-E / HWS-802H-E?

TFI sensor detach failure Likely causes: TFI sensor disconnected from pipe. Check TFI sensor attachment to pipe.

Toshiba HWS-802XWHT6-E 8kW Heat Pump: Specs & Faults

Engineer's overview

The Toshiba HWS-802XWHT6-E is a split-system air-source heat pump consisting of an outdoor unit and an indoor hydro unit containing a 3-phase backup heater. As part of the ESTIA range, it employs DC inverter technology to modulate output based on demand, achieving a COP of 4.08 at A7/W35 conditions. The system is designed for space heating and domestic hot water production, supporting a maximum flow temperature of 55°C. This specific model is paired with the HWS-802H-E outdoor unit.

The outdoor unit measures 890mm in height, 900mm in width, and 320mm in depth, with a weight of 63kg. It contains 1.8kg of R410A refrigerant and is rated for operation in ambient temperatures as low as -20°C. Sound pressure levels are recorded at 49 dB at a distance of one metre, with a dedicated quiet mode available for noise-sensitive environments. For installation, engineers must ensure minimum clearances of 300mm at the sides, 600mm at the front, and 150mm behind the unit to maintain adequate airflow across the heat exchanger.

The indoor hydro unit has dimensions of 925mm x 525mm x 355mm and a dry weight of 50kg. The unit requires a minimum water flow rate of 17.5 litres per minute to prevent flow-related errors and ensure efficient heat transfer. It is compatible with Toshiba’s range of hot water cylinders, including the HWS-1501CSHM3-E, HWS-2101CSHM3-E, and HWS-3001CSHM3-E models. The hydraulic circuit is rated for a maximum operating pressure of 3 bar.

Electrical requirements include a 230V, 50Hz supply with a maximum power consumption of 1.859kW for the heat pump cycle. The system requires a 25A MCB for circuit protection. Control is managed via the HWS-AMS11E remote controller, which supports weather compensation to optimize efficiency based on external temperature fluctuations. Maintenance protocols require annual inspections, including insulation resistance measurements for power and heater circuits, and refrigerant leak testing. The water heat exchanger must be checked for debris, and the internal strainer cleaned to maintain the required 17.5 lpm flow rate. Given the use of R410A refrigerant, F-Gas certification is mandatory for any work involving the refrigerant circuit. The system includes advanced diagnostics, with fault codes such as A01 (flow error) and P03 (outlet temperature error) providing specific data points for rapid troubleshooting.

HWS-802XWHT6-E / HWS-802H-E fault codes

Every fault code listed in the manufacturer brochure, with likely causes and engineer actions. Each code has a permalink — paste a URL like https://www.boilertag.com/heat-pumps/toshiba/hws-802xwht6-e-hws-802h-e#fault-a01 to jump straight to the entry.

Complete list of fault codes for this Toshiba HWS-802XWHT6-E / HWS-802H-E
Code	Meaning	Details
A01Lockout	Pump or flowing quantity error Show causes & actions Detected by TC sensor (TC ≥ 63°C) or flow switch abnormality (no signal 2 min after pump start). Likely causes Almost no or little water flow Not enough vent air Dirt clogging in the water piping system Water piping is too long Disconnection of the flow switch connector Engineer action Check water flow, vent air, clean strainer, check flow switch connection and operation.	Details
A02Lockout	Temperature increase error (heating) Show causes & actions When one of the TWI, TWO and THO sensors exceeds 70°C. Likely causes Defective TWI, TWO, or THO sensors Defect of the backup heater (automatic reset thermostat) Hot water from boiler or other circuits entering Engineer action Check sensors, check backup heater operation, correct water circuit if necessary.	Details
A03Lockout	Temperature increase error (hot water supply) Show causes & actions When the TTW sensor exceeds 85°C. Likely causes Defective TTW sensor Defective hot water cylinder thermal cut-out Engineer action Check TTW sensor and hot water cylinder thermal cut-out.	Details
A04Lockout	Antifreeze operation error Show causes & actions Freeze prevention control activated due to low water temperatures. Likely causes Little water flow Dirt clogging Heater power circuit failure Defective sensors (TWI, TWO, TC) Engineer action Check water flow, heater power supply, and sensor characteristics.	Details
A05Lockout	Piping antifreeze operation error Show causes & actions Heater activation fails to raise water temperature above 5°C after 30 minutes. Likely causes Heater power circuit failure Defective sensors Disconnection of the backup heater Engineer action Check heater power circuit and backup heater connection.	Details
A07Lockout	Pressure switch operation Show causes & actions Pressure switch operates for 300 sec continuously during heat pump operation. Likely causes Little water flow Defect of the flow switch Defect in the pressure switch Engineer action Check water flow, flow switch, and pressure switch.	Details
A08Lockout	Low pressure sensor operation error Show causes & actions Low pressure sensor detected 0.2 MPa or less. Likely causes Little water flow Defect of the flow switch Prolonged defrosting Defect in the low pressure sensor Engineer action Check water flow and low pressure sensor.	Details
A09Lockout	Overheat protection operation Show causes & actions Thermostat of the backup heater activates. Likely causes No water (heating without water) No water flow Defect of the flow switch Defect of the backup heater Engineer action Check water level, flow switch, and backup heater thermostat.	Details
A11Lockout	Operation of the release protection Show causes & actions When the TWO release counts to 10. Likely causes Almost no water flow Defect of the flow switch Defective TWO sensor Engineer action Check water flow and TWO sensor.	Details
A12Lockout	Heating or Hot water supply heater failure Show causes & actions Heater backup operation fails to reach target temperatures within 1 hour. Likely causes Large heating load Heater power circuit failure Defective backup or cylinder heater Engineer action Check heater power circuit and heater elements.	Details
E03Lockout	Communication error (Hydro - Remote) Show causes & actions No regular communication from the remote control for 3 min. Likely causes Remote control connection failure Defective remote control Engineer action Check remote control wiring and unit.	Details
E04Lockout	Communication error (Hydro - Outdoor) Show causes & actions Serial signal cannot be received from outdoor unit. Likely causes Miswiring of crossover cables Serial circuit failure Engineer action Check serial circuit and interconnecting wiring.	Details
F03Lockout	TC sensor error Show causes & actions Open or short circuit in the heat exchange temperature sensor. Likely causes Defective TC sensor Loose connection Engineer action Check resistance and connection of TC sensor.	Details
F10Lockout	TWI sensor error Show causes & actions Open or short circuit in the water inlet temperature sensor. Likely causes Defective TWI sensor Loose connection Engineer action Check resistance and connection of TWI sensor.	Details
F11Lockout	TWO sensor error Show causes & actions Open or short circuit in the water outlet temperature sensor. Likely causes Defective TWO sensor Loose connection Engineer action Check resistance and connection of TWO sensor.	Details
F14Lockout	TTW sensor error Show causes & actions Open or short circuit in the hot water cylinder sensor. Likely causes Defective TTW sensor Loose connection Engineer action Check resistance and connection of TTW sensor.	Details
F17Lockout	TFI sensor error Show causes & actions Open or short circuit in the floor temperature sensor. Likely causes Defective TFI sensor Loose connection Engineer action Check resistance and connection of TFI sensor.	Details
F18Lockout	THO sensor error Show causes & actions Open or short circuit in the heater outlet temperature sensor. Likely causes Defective THO sensor Loose connection Engineer action Check resistance and connection of THO sensor.	Details
F19Lockout	THO sensor detach failure Show causes & actions When TWO–THO > 15K is detected for 30 sec. Likely causes THO sensor disconnected from pipe Engineer action Check THO sensor attachment to pipe.	Details
F20Lockout	TFI sensor detach failure Show causes & actions When TWO–TFI > 30K or TFI < TWI–5K is detected. Likely causes TFI sensor disconnected from pipe Engineer action Check TFI sensor attachment to pipe.	Details
F23Lockout	Low pressure sensor error Show causes & actions When PS < 0.07 MPa is detected for 2 sec or more. Likely causes Disconnection of low pressure sensor Defective low pressure sensor Engineer action Check connection and resistance of low pressure sensor.	Details
H01Lockout	Compressor breakdown Show causes & actions Operation frequency lowers due to current release or excess current detected. Likely causes Power supply voltage abnormality Over-loaded refrigeration cycle Service valve not fully open Engineer action Check power supply, refrigeration cycle load, and service valves.	Details
H02Lockout	Compressor lock Show causes & actions Compressor fails to activate within 20 seconds. Likely causes Defective compressor (locked) Defective compressor wiring (open phase) Engineer action Check compressor wiring and replace compressor if locked.	Details
H04Lockout	Operation of case thermostat Show causes & actions When the case thermostat exceeds 125°C. Likely causes Refrigerant gas leak Defective case thermostat Service valve closed Defective PMV Kinked piping Engineer action Check for leaks, check thermostat, ensure valves are open, check PMV and piping.	Details
P03Lockout	Outlet temperature error Show causes & actions Discharge temperature (TD) exceeds 111°C. Likely causes Refrigerant gas leak Defective PMV Defective TD sensor Engineer action Check for leaks, check PMV operation, and TD sensor resistance.	Details
P20Lockout	High pressure protection operation Show causes & actions Abnormal stop due to high pressure release control. Likely causes Service valve closed Defective PMV Outdoor fan system failure Over-filling of refrigerant Engineer action Check service valves, PMV, outdoor fan, and refrigerant charge level.	Details

Common HWS-802XWHT6-E / HWS-802H-E problems & troubleshooting

Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.

How to fix the HWS-802XWHT6-E / HWS-802H-E pump or flowing quantity errorLockout

Engineer: Check water flow, vent air, clean strainer, check flow switch connection and operation.

Triggered by fault code A01.

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (heating)Lockout

Engineer: Check sensors, check backup heater operation, correct water circuit if necessary.

Triggered by fault code A02.

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (hot water supply)Lockout

Engineer: Check TTW sensor and hot water cylinder thermal cut-out.

Triggered by fault code A03.

HWS-802XWHT6-E / HWS-802H-E

HWS-802XWHT6-E / HWS-802H-E at a glance

Register this Toshiba HWS-802XWHT6-E / HWS-802H-E on BoilerTag

HWS-802XWHT6-E / HWS-802H-E data sheet

Engineer's overview

HWS-802XWHT6-E / HWS-802H-E fault codes

Common HWS-802XWHT6-E / HWS-802H-E problems & troubleshooting

How to fix the HWS-802XWHT6-E / HWS-802H-E pump or flowing quantity errorLockout

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (heating)Lockout

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (hot water supply)Lockout

How to fix the HWS-802XWHT6-E / HWS-802H-E antifreeze operation error

HWS-802XWHT6-E / HWS-802H-E FAQs

Every boiler brochure, free with BoilerTag

Working on a Toshiba HWS-802XWHT6-E / HWS-802H-E?

How to fix the HWS-802XWHT6-E / HWS-802H-E piping antifreeze operation errorLockout

Likely causes that trigger multiple HWS-802XWHT6-E / HWS-802H-E fault codes

HWS-802XWHT6-E / HWS-802H-E at a glance

Register this Toshiba HWS-802XWHT6-E / HWS-802H-E on BoilerTag

HWS-802XWHT6-E / HWS-802H-E data sheet

Engineer's overview

HWS-802XWHT6-E / HWS-802H-E fault codes

Common HWS-802XWHT6-E / HWS-802H-E problems & troubleshooting

How to fix the HWS-802XWHT6-E / HWS-802H-E pump or flowing quantity errorLockout

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (heating)Lockout

How to fix the HWS-802XWHT6-E / HWS-802H-E temperature increase error (hot water supply)Lockout

How to fix the HWS-802XWHT6-E / HWS-802H-E antifreeze operation error

HWS-802XWHT6-E / HWS-802H-E FAQs

What refrigerant does the Toshiba HWS-802XWHT6-E use?

What does fault code A01 mean on a Toshiba HWS-802XWHT6-E?

What does fault code P03 mean on a Toshiba HWS-802XWHT6-E?

What are the dimensions of the Toshiba HWS-802XWHT6-E outdoor unit?

Which hot water cylinders are compatible with the HWS-802XWHT6-E?

Is the Toshiba HWS-802XWHT6-E a monobloc or split system?

What is the minimum operating temperature for the HWS-802XWHT6-E?

Every boiler brochure, free with BoilerTag

Other Toshiba heat pumps

Working on a Toshiba HWS-802XWHT6-E / HWS-802H-E?

How to fix the HWS-802XWHT6-E / HWS-802H-E piping antifreeze operation errorLockout

Likely causes that trigger multiple HWS-802XWHT6-E / HWS-802H-E fault codes