What is the Toshiba HWS-1402XWHT6-E?

The Toshiba HWS-1402XWHT6-E is a 14kW split air-source heat pump with a 4.45 COP and a 55°C maximum flow temperature. It is designed for domestic heating and hot water in larger UK homes, utilizing a DC inverter and R410A refrigerant.

How do I register a Toshiba HWS-1402XWHT6-E with BoilerTag?

Scan the QR code on the BoilerTag sticker after installation and confirm the model details, which will pre-fill from the catalogue. Record the installation date and your Gas Safe or F-Gas number to ensure the service log is permanent and publicly viewable. 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-1402XWHT6-E?

The Coefficient of Performance (COP) is 4.45 when measured at an outdoor air temperature of 7°C and a water outlet temperature of 35°C (A7/W35). This indicates that for every 1kW of electricity consumed, the unit provides 4.45kW of heat energy.

What refrigerant does the Toshiba HWS-1402XWHT6-E use?

This model uses R410A refrigerant. The outdoor unit comes with a factory charge of 2.7kg, and as it is a split system, F-Gas certification is required for the installation and handling of the refrigerant pipework.

What does fault code A01 mean on a Toshiba ESTIA?

Fault code A01 indicates a pump or water flow quantity error. This is typically caused by insufficient water flow, air trapped in the system, dirt clogging the pipework, or a defect in the flow switch or its electrical connection.

What are the dimensions of the Toshiba HWS-1402XWHT6-E indoor unit?

The indoor hydro unit measures 925mm in height, 525mm in width, and 355mm in depth. It has a net weight of 54kg and must be installed in a location that allows for these dimensions plus necessary service clearances.

What is the maximum flow temperature for the HWS-1402XWHT6-E?

The maximum water flow temperature is 55°C. This temperature is suitable for domestic hot water production and heating systems using appropriately sized radiators or underfloor heating circuits.

Which cylinders are compatible with the Toshiba HWS-1402XWHT6-E?

Compatible Toshiba hot water cylinders include the HWS-1501CSHM3-E, HWS-2101CSHM3-E, and HWS-3001CSHM3-E models. These are specifically designed to work with the ESTIA hydro unit for efficient domestic hot water production.

What is fault code E04 on the Toshiba ESTIA?

Fault code E04 represents a regular communication error between the indoor hydro unit and the outdoor unit. This usually points to a serial signal failure, which may be caused by miswiring of the crossover cable or a defect in the serial circuit.

How loud is the Toshiba HWS-1402XWHT6-E?

The unit has a sound pressure level of 29 dB when measured at a distance of one metre. It also features a quiet mode that can be activated via the remote controller to further reduce noise during specific times.

What does fault code A01 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Pump or flowing quantity error Likely causes: Almost no or little water flow; Not enough vent air; Dirt clogging in water piping; Water piping too long; Disconnection of flow switch connector; Defect of flow switch. Check water flow and air vent. Inspect for dirt clogging. Check flow switch connect…

What does fault code A02 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Temperature increase error (heating) Likely causes: Sensor defect; Defect of backup heater (automatic reset thermostat). Check TWI, TWO, THO sensors. Check backup heater.

What does fault code A03 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

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

What does fault code A04 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Antifreeze operation Likely causes: Little water flow; Dirt clogging; Piping too long; Heater power circuit failure. Check water flow and heater power circuit.

What does fault code A05 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Piping antifreeze operation Likely causes: Heater power circuit failure; Sensor defect; Backup heater disconnection. Check heater power circuit and sensors.

What does fault code A07 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Pressure switch operation Likely causes: Little water flow; Flow switch defect; Pressure switch defect. Check water flow and pressure switch.

What does fault code A08 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Low pressure sensor operation error Likely causes: Little water flow; Flow switch defect; On-load cooling or prolonged defrosting; Low pressure sensor defect. Check water flow and low pressure sensor.

What does fault code A09 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Overheat protection operation Likely causes: No water or no water flow; Flow switch defect; Backup heater defect. Check water level and flow switch.

What does fault code A11 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Operation of the release protection Likely causes: No water flow; Flow switch defect; TWO sensor defect. Check water flow and TWO sensor.

What does fault code A12 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Heating, hot water heater Likely causes: Large load of heating or hot water supply; Heater power circuit failure. Check heater power circuit.

What does fault code E03 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Regular communication error between hydro unit and remote controller Likely causes: Remote control connection defect; Remote control defect. Check remote control connection.

What does fault code E04 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Regular communication error between hydro unit and outdoor unit Likely causes: Serial circuit defect; Miswiring of crossover. Check serial circuit and wiring.

What does fault code F03 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TC sensor error Likely causes: TC sensor resistance or connection defect. Check TC sensor.

What does fault code F10 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TWI sensor error Likely causes: TWI sensor resistance or connection defect. Check TWI sensor.

What does fault code F11 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TWO sensor error Likely causes: TWO sensor resistance or connection defect. Check TWO sensor.

What does fault code F14 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TTW sensor error Likely causes: TTW sensor resistance or connection defect. Check TTW sensor.

What does fault code F17 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TFI sensor error Likely causes: TFI sensor resistance or connection defect. Check TFI sensor.

What does fault code F18 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

THO sensor error Likely causes: THO sensor resistance or connection defect. Check THO sensor.

What does fault code F19 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

Detection of THO disconnection error Likely causes: THO sensor disconnection. Check THO sensor connection.

What does fault code F20 mean on the Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

TFI sensor error Likely causes: TFI sensor disconnection. Check TFI sensor connection.

Toshiba HWS-1402XWHT6-E 14kW Heat Pump Specs & Faults

Engineer's overview

The Toshiba HWS-1402XWHT6-E is a 14kW split air-source heat pump within the ESTIA product family. This DC inverter-driven system is designed for high-capacity domestic heating and hot water production, utilizing R410A refrigerant with a factory charge of 2.7kg. The system architecture consists of an outdoor unit (HWS-1402H-E) and an indoor hydro unit (HWS-1402XWHT6-E), providing flexibility in installation where internal space or external noise constraints are factors.

Performance-wise, the unit achieves a nominal capacity of 14kW at an ambient air temperature of 7°C and a water flow temperature of 35°C (A7/W35), yielding a Coefficient of Performance (COP) of 4.45. It is engineered to maintain operation in extreme conditions, with a minimum outdoor operating temperature of -20°C. The maximum flow temperature is capped at 55°C, making it suitable for well-insulated properties with correctly sized emitters or underfloor heating systems. The system also features a quiet mode to reduce noise emissions during sensitive hours.

Physically, the outdoor unit measures 1340mm in height, 900mm in width, and 320mm in depth, with a net weight of 90kg. The indoor hydro unit is more compact at 925mm high, 525mm wide, and 355mm deep, weighing 54kg. For hydraulic integration, the system requires a minimum water flow rate of 13 litres per minute and operates at a maximum pressure of 3 bar. It features a reverse cycle defrost method to maintain efficiency during colder months, preventing ice build-up on the evaporator coils.

Electrical requirements for this single-phase 230V/50Hz appliance include a maximum power consumption of 3.945kW and a startup current of 18.1A. Control is managed via the HWS-AMS11E remote controller, which supports weather compensation to optimize the heating curve based on external temperatures. This allows the system to adjust the flow temperature dynamically, improving seasonal efficiency.

For maintenance and diagnostics, the ESTIA range utilizes a comprehensive fault code system. Common codes include A01, which indicates a pump or flow quantity error, often caused by air in the system, dirt clogging, or a defect in the flow switch. Communication errors between the hydro unit and the remote controller are flagged as E03, while serial signal failures between the indoor and outdoor units trigger E04. Temperature sensor errors, such as F10 (water inlet) and F11 (water outlet), allow engineers to pinpoint specific component failures. Annual servicing is mandatory, requiring insulation measurements with a mega tester, power source voltage checks (230V +/- 23V), and refrigerant leak inspections by F-Gas certified engineers. Compatible cylinders include the HWS-1501, 2101, and 3001 series.

HWS-1402XWHT6-E / HWS-1402H-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-1402xwht6-e-hws-1402h-e#fault-a01 to jump straight to the entry.

Complete list of fault codes for this Toshiba HWS-1402XWHT6-E / HWS-1402H-E
Code	Meaning	Details
A01	Pump or flowing quantity error Show causes & actions Detected by TC sensor (TC >= 63C) 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 water piping Water piping too long Disconnection of flow switch connector Defect of flow switch User action Contact service engineer. Engineer action Check water flow and air vent. Inspect for dirt clogging. Check flow switch connection and functionality.	Details
A02	Temperature increase error (heating) Show causes & actions When one of TWI, TWO and THO sensors exceeds 70C. Likely causes Sensor defect Defect of backup heater (automatic reset thermostat) Engineer action Check TWI, TWO, THO sensors. Check backup heater. Reset procedure Automatic reset	Details
A03	Temperature increase error (hot water supply) Show causes & actions When the TTW sensor exceeds 85C. Likely causes TTW sensor defect Hot water cylinder thermal cut-out defect Engineer action Check TTW sensor and hot water cylinder thermal cut-out. Reset procedure Automatic reset	Details
A04	Antifreeze operation Show causes & actions Freeze protection conditions detected by sensors. Likely causes Little water flow Dirt clogging Piping too long Heater power circuit failure Engineer action Check water flow and heater power circuit.	Details
A05	Piping antifreeze operation Show causes & actions Heater activation does not achieve 5C after 30 min. Likely causes Heater power circuit failure Sensor defect Backup heater disconnection Engineer action Check heater power circuit and sensors. Reset procedure Automatic reset	Details
A07	Pressure switch operation Show causes & actions Pressure switch operates for 300 sec continuously. Likely causes Little water flow Flow switch defect Pressure switch defect Engineer action Check water flow and pressure switch.	Details
A08	Low pressure sensor operation error Show causes & actions Low pressure sensor detected 0.2 MPa or less. Likely causes Little water flow Flow switch defect On-load cooling or prolonged defrosting Low pressure sensor defect Engineer action Check water flow and low pressure sensor.	Details
A09	Overheat protection operation Show causes & actions Backup heater thermostat activates. Likely causes No water or no water flow Flow switch defect Backup heater defect Engineer action Check water level and flow switch.	Details
A11	Operation of the release protection Show causes & actions TWO release counts to 10. Likely causes No water flow Flow switch defect TWO sensor defect Engineer action Check water flow and TWO sensor.	Details
A12	Heating, hot water heater Show causes & actions Antifreeze control detected under specific TWI/TTW conditions. Likely causes Large load of heating or hot water supply Heater power circuit failure Engineer action Check heater power circuit. Reset procedure Automatic reset	Details
E03	Regular communication error between hydro unit and remote controller Show causes & actions No communication for 3 min. Likely causes Remote control connection defect Remote control defect Engineer action Check remote control connection. Reset procedure Automatic reset	Details
E04	Regular communication error between hydro unit and outdoor unit Show causes & actions Serial signal cannot be received from outdoor. Likely causes Serial circuit defect Miswiring of crossover Engineer action Check serial circuit and wiring. Reset procedure Automatic reset	Details
F03	TC sensor error Show causes & actions Open or short circuit in heat exchange temperature sensor. Likely causes TC sensor resistance or connection defect Engineer action Check TC sensor. Reset procedure Automatic reset	Details
F10	TWI sensor error Show causes & actions Open or short circuit in water inlet temperature sensor. Likely causes TWI sensor resistance or connection defect Engineer action Check TWI sensor. Reset procedure Automatic reset	Details
F11	TWO sensor error Show causes & actions Open or short circuit in water outlet temperature sensor. Likely causes TWO sensor resistance or connection defect Engineer action Check TWO sensor. Reset procedure Automatic reset	Details
F14	TTW sensor error Show causes & actions Open or short circuit in hot water cylinder sensor. Likely causes TTW sensor resistance or connection defect Engineer action Check TTW sensor. Reset procedure Automatic reset	Details
F17	TFI sensor error Show causes & actions Open or short circuit in floor temperature sensor. Likely causes TFI sensor resistance or connection defect Engineer action Check TFI sensor. Reset procedure Automatic reset	Details
F18	THO sensor error Show causes & actions Open or short circuit in heater outlet temperature sensor. Likely causes THO sensor resistance or connection defect Engineer action Check THO sensor. Reset procedure Automatic reset	Details
F19	Detection of THO disconnection error Show causes & actions TWO-THO > 15K detected for 30 sec. Likely causes THO sensor disconnection Engineer action Check THO sensor connection.	Details
F20	TFI sensor error Show causes & actions TWO-TFI > 30K or TFI < TWI-5K detected. Likely causes TFI sensor disconnection Engineer action Check TFI sensor connection.	Details
F23	Low pressure sensor error Show causes & actions PS < 0.07 MPa detected for 2 sec or more. Likely causes Low pressure sensor disconnection Low pressure sensor resistance defect Engineer action Check low pressure sensor. Reset procedure Automatic reset	Details
F29	EEROM error Show causes & actions Inconsistency detected in non-volatile memory. Likely causes Water heat exchange control board defect Engineer action Replace water heat exchange control board.	Details
F30	Extended IC error Show causes & actions Extended IC is abnormal. Likely causes Water heat exchange control board defect Engineer action Replace water heat exchange control board.	Details
L07	Communication error Show causes & actions Individual hydro units have a group line. Likely causes Water heat exchange control board defect Engineer action Replace water heat exchange control board.	Details
L09	Communication error Show causes & actions Capability of hydro unit has not been set. Likely causes FC01 capability specification setting error Engineer action Check FC01 setting.	Details
L16	Setting error Show causes & actions ZONE1 not set while ZONE2 is set. Likely causes DP-SW12_2,3 setting error Engineer action Check DP-SW12 settings.	Details
F04	TD sensor error Show causes & actions Open or short circuit in discharge temperature sensor. Likely causes TD sensor resistance or connection defect Engineer action Check TD sensor.	Details
F06	TE sensor error Show causes & actions Open or short circuit in heat exchange temperature sensor. Likely causes TE sensor resistance or connection defect Engineer action Check TE sensor.	Details
F07	TL sensor error Show causes & actions Open or short circuit in heat exchange temperature sensor. Likely causes TL sensor resistance or connection defect Engineer action Check TL sensor.	Details
F08	TO sensor error Show causes & actions Open or short circuit in outdoor temperature sensor. Likely causes TO sensor resistance or connection defect Engineer action Check TO sensor.	Details
F12	TS sensor error Show causes & actions Open or short circuit in suction temperature sensor. Likely causes TS sensor resistance or connection defect Engineer action Check TS sensor.	Details
F13	TH sensor error Show causes & actions Open or short circuit in heat-sink temperature sensor. Likely causes TH sensor resistance or connection defect Engineer action Check TH sensor.	Details
F15	TE, TS sensors error Show causes & actions Open or short circuit in temperature sensors. Likely causes Wrong installation of TE and TS sensors Engineer action Check installation of TE and TS sensors.	Details
F31	EEPROM error Show causes & actions Outdoor unit EEPROM failure. Likely causes Outdoor control board defect Engineer action Check outdoor control board.	Details
H01	Compressor breakdown Show causes & actions Compressor stops due to current release or limit control. Likely causes Power supply voltage defect Over-loaded refrigeration cycle Service valve not fully open Engineer action Check power supply and service valves.	Details
H02	Compressor lock Show causes & actions Compressor activation not completed. Likely causes Compressor lock Compressor wiring defect Engineer action Replace compressor or check wiring.	Details
H03	Defect in the current detection circuit Show causes & actions Current detection circuit failure. Likely causes Outdoor inverter control board defect Engineer action Replace outdoor inverter control board.	Details
H04	Operation of case thermostat Show causes & actions Case thermostat exceeds 125C. Likely causes Gas leak Case thermostat defect Service valve closed PMV defect Kinked piping Engineer action Check refrigeration cycle and case thermostat.	Details
L10	Unset service PC board jumper Show causes & actions Jumpers J800-J803 not cut. Likely causes Service board installation error Engineer action Cut J800-J803.	Details
L29	Communication between outdoor PC board MUCs error Show causes & actions No communication signal between IPDU and CDB. Likely causes Outdoor control board defect Engineer action Replace outdoor control board.	Details
P03	The outlet temperature error Show causes & actions Discharge temperature sensor (TD) exceeds 111C. Likely causes Gas leak PMV defect TD sensor resistance defect Engineer action Check refrigeration cycle and TD sensor.	Details
P04	The high pressure switch error Show causes & actions High pressure switch activation. Likely causes High pressure switch defect Engineer action Check high pressure switch.	Details
P05	The power supply voltage error Show causes & actions Power supply voltage extremely high or low. Likely causes Power supply voltage defect Engineer action Check power supply voltage (230V +/- 23V).	Details
P07	Overheating of heat-sink error Show causes & actions Heat-sink exceeds 105C. Likely causes Loose screws in motor drive element Radiation grease not applied Ventilation flue blocked Engineer action Check heat-sink fastening and grease. Clear ventilation.	Details
P15	Detection of gas leak Show causes & actions TD exceeds 106C or TS exceeds 60C/40C for 10 min. Likely causes Gas leak Service valve closed PMV defect Kinked piping Sensor resistance defect Engineer action Check refrigeration cycle and sensors.	Details
P19	The 4-way valve inversion error Show causes & actions TE exceeds 30C or TS exceeds 50C during heat pump operation. Likely causes 4-way valve unit or coil defect PMV defect Sensor resistance defect Engineer action Check 4-way valve and sensors.	Details
P20	High pressure protection operation Show causes & actions Abnormal stop due to high pressure release control. Likely causes Service valve closed PMV defect Outdoor fan system defect Over-filling of refrigerant Sensor resistance defect Engineer action Check service valves, PMV, and fan system.	Details
P22	Outdoor fan system error Show causes & actions DC fan rotor position detection NG or abnormal current. Likely causes Motor fan lock Fan motor cable connector defect Power supply voltage defect Engineer action Check motor fan and connections.	Details
P26	Short circuit of the compressor driver element error Show causes & actions Abnormal short circuit of IGBT detected. Likely causes Control board defect Compressor rare short Engineer action Check control board and compressor.	Details
P29	Compressor rotor position error Show causes & actions Rotor position cannot be detected. Likely causes Inverter control board defect Compressor short circuit Engineer action Replace inverter control board or compressor.	Details
E01	No communication between hydro unit and remote controller Show causes & actions Disconnection of crossover detected on remote control side. Likely causes Remote control crossover defect Remote control defect Hydro power supply wiring defect Engineer action Check crossover and power supply. Reset procedure Automatic reset	Details
E02	Defect in the signal transmission to the hydro unit Show causes & actions Detected on the remote control side. Likely causes Transmitter circuit inside remote control defect Engineer action Replace remote control. Reset procedure Automatic reset	Details
E09	Several remote control base units Show causes & actions Detected on the remote control side. Likely causes More than one base unit configured Engineer action Check base unit configuration.	Details

Common HWS-1402XWHT6-E / HWS-1402H-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-1402XWHT6-E / HWS-1402H-E pump or flowing quantity error

User: Contact service engineer.

Engineer: Check water flow and air vent. Inspect for dirt clogging. Check flow switch connection and functionality.

Triggered by fault code A01.

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (heating)

Engineer: Check TWI, TWO, THO sensors. Check backup heater.

Triggered by fault code A02.

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (hot water supply)

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

Triggered by fault code A03.

How to fix the HWS-1402XWHT6-E / HWS-1402H-E antifreeze operation

Engineer: Check water flow and heater power circuit.

Triggered by fault code .

HWS-1402XWHT6-E / HWS-1402H-E

HWS-1402XWHT6-E / HWS-1402H-E at a glance

HWS-1402XWHT6-E / HWS-1402H-E

HWS-1402XWHT6-E / HWS-1402H-E at a glance

Register this Toshiba HWS-1402XWHT6-E / HWS-1402H-E on BoilerTag

HWS-1402XWHT6-E / HWS-1402H-E data sheet

Engineer's overview

HWS-1402XWHT6-E / HWS-1402H-E fault codes

Common HWS-1402XWHT6-E / HWS-1402H-E problems & troubleshooting

How to fix the HWS-1402XWHT6-E / HWS-1402H-E pump or flowing quantity error

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (heating)

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (hot water supply)

How to fix the HWS-1402XWHT6-E / HWS-1402H-E antifreeze operation

HWS-1402XWHT6-E / HWS-1402H-E FAQs

Every boiler brochure, free with BoilerTag

Working on a Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

How to fix the HWS-1402XWHT6-E / HWS-1402H-E piping antifreeze operation

Likely causes that trigger multiple HWS-1402XWHT6-E / HWS-1402H-E fault codes

HWS-1402XWHT6-E / HWS-1402H-E at a glance

HWS-1402XWHT6-E / HWS-1402H-E at a glance

Register this Toshiba HWS-1402XWHT6-E / HWS-1402H-E on BoilerTag

HWS-1402XWHT6-E / HWS-1402H-E data sheet

Engineer's overview

HWS-1402XWHT6-E / HWS-1402H-E fault codes

Common HWS-1402XWHT6-E / HWS-1402H-E problems & troubleshooting

How to fix the HWS-1402XWHT6-E / HWS-1402H-E pump or flowing quantity error

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (heating)

How to fix the HWS-1402XWHT6-E / HWS-1402H-E temperature increase error (hot water supply)

How to fix the HWS-1402XWHT6-E / HWS-1402H-E antifreeze operation

HWS-1402XWHT6-E / HWS-1402H-E FAQs

What refrigerant does the Toshiba HWS-1402XWHT6-E use?

What does fault code A01 mean on a Toshiba ESTIA?

What are the dimensions of the Toshiba HWS-1402XWHT6-E indoor unit?

What is the maximum flow temperature for the HWS-1402XWHT6-E?

Which cylinders are compatible with the Toshiba HWS-1402XWHT6-E?

What is fault code E04 on the Toshiba ESTIA?

How loud is the Toshiba HWS-1402XWHT6-E?

Every boiler brochure, free with BoilerTag

Other Toshiba heat pumps

Working on a Toshiba HWS-1402XWHT6-E / HWS-1402H-E?

How to fix the HWS-1402XWHT6-E / HWS-1402H-E piping antifreeze operation

Likely causes that trigger multiple HWS-1402XWHT6-E / HWS-1402H-E fault codes