Intergas
The Intergas Xtend_Mono_Installation_Instructions is a 5kW hybrid monobloc heat pump with an A++ ErP rating, a COP of 4.68, and R32 refrigerant.
The Intergas Xtend_Mono_Installation_Instructions is a 5kW hybrid air-to-water heat pump system designed for integration with existing heating infrastructures. Comprising an outdoor monobloc unit and a compact indoor controller, it utilizes R32 refrigerant to deliver a nominal heat output of 5.04kW at A7/W35 conditions. This technical guide provides engineers with critical installation data, including electrical requirements, hydraulic parameters, and a comprehensive directory of F-series and n-series fault codes for diagnostic support and system maintenance.
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Full technical specifications extracted from the manufacturer brochure. Empty sections are hidden.
The Intergas Xtend_Mono_Installation_Instructions is a hybrid-ready heat pump solution specifically engineered for the UK domestic market. The system is centered around the Xtend 5 mono FT, which provides a nominal capacity of 5kW at an ambient temperature of 7°C and a flow temperature of 35°C. At these conditions, the unit achieves a COP of 4.68, contributing to its A++ ErP rating. Even as outdoor temperatures drop to -7°C, the unit maintains a capacity of 3.1kW, with an operational range extending down to -15°C.
Physically, the system is split between an outdoor monobloc unit (Xtend-HB-AWHPM5FT) and a small indoor unit (Xtend-HB-CUM05FT). The outdoor unit measures 689mm in height and 1000mm in width, weighing 48kg. It operates with a sound power level of 49 dB(LwA), making it suitable for various residential settings. The indoor unit is exceptionally compact at 557mm high and only 163.5mm wide, weighing just 5kg, which simplifies installation in constrained spaces such as utility rooms or cupboards.
The hydraulic circuit requires a minimum water flow rate of 8 litres per minute and utilizes 22mm pipe connections. The system is designed to operate at a maximum pressure of 3 bar. Notably, the Xtend does not strictly require a buffer tank, though system volume must be considered during design. For control, the unit is OpenTherm compatible and integrates with the Intergas Comfort Touch room thermostat and Gateway, allowing for weather compensation and remote app-based management.
Electrical installation requires a 230V single-phase supply with a maximum power consumption of 1.8kW, protected by a 16A MCB. The unit uses 0.85kg of R32 refrigerant, which has a GWP of 675. Maintenance is required every 12 months, involving filter cleaning, evaporator fin inspection, and electrical connection checks.
For diagnostics, the Xtend_Mono_Installation_Instructions uses a dual-tier notification system. Lockout faults (F-codes) like F001 indicate no flow in the CH circuit, while notification codes (n-codes) like n001 signal low system pressure. The system also includes a bypass mode (F254) to force heat requests to the boiler during commissioning or troubleshooting. Engineers should note that the unit is configured for a maximum flow temperature of 70°C, though efficiency is optimized at lower temperatures.
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/intergas/xtend-5-mono-ft#fault-f001 to jump straight to the entry.
| Code | Meaning | Details |
|---|---|---|
| F001Lockout | No flow in the CH circuit for at least 30 minutes. Show causes & actionsLikely causes
Engineer action Check the CH pump. Check the system for leaks. Check the system water pressure. | Details |
| F003Lockout | Value of external flow sensor T43 too high (>67°C) or Value of flow sensor T03 over 1 minute too high. (> 90 ºC) Show causes & actionsLikely causes
Engineer action Check the flow in the system. | Details |
| F009Lockout | Memory fault codes. Show causes & actionsLikely causes
Engineer action Reset the control unit. Replace the control unit. | Details |
| F010Lockout | Water temperature too low during defrost function. Show causes & actionsLikely causes
Engineer action CH flow too low. Check system flow. | Details |
| F018Lockout | Heat pump type not correctly configured. Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F019Lockout | Incorrect serial number in memory module. Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F020Lockout | Incorrect firmware. Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F022Lockout | Firmware version not compatible Show causes & actionsLikely causes
Engineer action Firmware needs an updating. Consult Intergas Heating Ltd. | Details |
| F023Lockout | XTP controller internal Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F024Lockout | XTP controller configuration Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F025Lockout | XTP controller communication Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| F026Lockout | Startup Show causes & actionsLikely causes
Engineer action Switch off the power at the fused spur for 1 minute, the re-establish. Replace the control unit. | Details |
| F037Lockout | Return sensor T04. Show causes & actionsLikely causes
Engineer action Check for any breakages/short circuits in the wiring for the sensor T04. Check whether the sensor T04 is connected correctly. Replace the sensor T04. | Details |
| F038Lockout | Flow sensor T03. Show causes & actionsLikely causes
Engineer action Check for any breakages/short circuits in the wiring for the sensor T03. Check whether the sensor T03 is connected correctly. Replace the sensor T03. | Details |
| F039Lockout | External flow sensor T43. Show causes & actionsLikely causes
Engineer action Check for any breakages/short circuits in the wiring for the sensor T43. Check whether the sensor T43 is connected correctly. Replace the sensor T43. | Details |
| F040Lockout | External outdoor sensor T42. Show causes & actionsLikely causes
Engineer action Check for any breakages/short circuits in the wiring for the sensor T42. Check whether the sensor T42 is connected correctly. Replace the sensor T42. | Details |
| F050Lockout | Fault within the outdoor unit Show causes & actionsLikely causes
Engineer action Access the control screen for additional information | Details |
| F051Lockout | Fault within the indoor unit Show causes & actionsLikely causes
Engineer action Access the control screen for additional information | Details |
| F254 | Bypass mode active Show causes & actionsNot a fault code as such, but a forced way to forward the heat request to the boiler. Likely causes
Engineer action Switch off the power at the fused spur then, press and hold the control button whilst re-establishing the power supply to clear the by-pass mode. | Details |
| n000 | Parameter settings outside range Show causes & actionsLikely causes
Engineer action Check the settings. | Details |
| n001 | System pressure too low, parameter P020 Show causes & actionsLikely causes
Engineer action Check for leaks The system water requires refilling or topping up. | Details |
| n002 | No water pressure Show causes & actionsLikely causes
Engineer action Check for leaks The system water requires refilling or topping up. | Details |
| n008 | XTP error heat pump (ODU) Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| n011 | Communication with the outdoor unit has been lost or the outdoor unit has an internal . Show causes & actionsLikely causes
Engineer action Access the Wifi control screen for additional information Check the wiring between the indoor unit and outdoor unit for breakages/short circuit. Check the connections in the outdoor unit. | Details |
| n013 | Condenser temperature too high: heating pump disengaged. Show causes & actionsLikely causes
Engineer action Potentially insufficient flow. System can not loose heat. | Details |
| n014 | Thermostat not connected. Show causes & actionsLikely causes
Engineer action Connect the Comfort Touch thermostat; see §8.8.5. | Details |
| n015 | Crankcase heater function Show causes & actionsLikely causes
Engineer action Possible loose connection to the outdoor unit Faulty resistance element. | Details |
| n016 | Abnormal Delta-T between the flow and return temperature values Show causes & actionsLikely causes
Engineer action Sensors T03 and T04 connected or mounted incorrectly. Check the system flow. | Details |
| n018 | Problem with memory. Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| n019 | Fault memory module Show causes & actionsLikely causes
Engineer action Check the wiring. Replace the memory module. | Details |
| n021 | No flow in the CH circuit for at least 30 seconds. Show causes & actionsLikely causes
Engineer action Venting program (max. 15 minutes) is started. Pump turns off for 60 seconds. Pump runs at maximum capacity. If sufficient flow is regained again for 30 seconds, the program will stop and the notification code will clear. | Details |
| n022 | Problem with automatic flow rate control Show causes & actionsLikely causes
Engineer action Probably air in the system, vent. | Details |
| n023 | System flow too low during commissioning Show causes & actionsLikely causes
Engineer action Check the CH-circuit for restrictions, debris, air or isolation valves closed. | Details |
| n024 | Remote flow system temperature sensor T43 gives an abnormal value Show causes & actionsLikely causes
Engineer action Check if the sensor is attached firmly. Check the connector on the main print. | Details |
| n026 | Clock not set Show causes & actionsLikely causes
Engineer action Set the clock | Details |
| n027 | Problem in the Clock operation Show causes & actionsLikely causes
Engineer action Possible hardware error Consult Intergas Heating Ltd. | Details |
| n028 | Notification code that arises because the outdoor unit regularly experiences problems. Show causes & actionsLikely causes
Engineer action Consult Intergas Heating Ltd. | Details |
| n030 | Remote flow system temperature sensor T43 not installed. Show causes & actionsLikely causes
Engineer action Check in the WiFi control screen if; P066 = 4 (Boiler control On/Off), P123 = 1 (Yes), P123 = 3 (Adjustable relay output). | Details |
| n032 | Defrost is taking to long Show causes & actionsLikely causes
Engineer action Possible a cooling error Possible that the outdoor unit is fully exposed to the wind. | Details |
| n039 | Problem with external flow temperature sensor T43 Show causes & actionsLikely causes
Engineer action Check the position and connection of the sensor on the flow pipework. Check wiring. Replace if necessary. | Details |
| n040 | Problem with external outdoor sensor T42 Show causes & actionsLikely causes
Engineer action Check wiring. Replace if necessary. | Details |
| n041 | Problem with refrigerant liquid sensor. Show causes & actionsLikely causes
Engineer action Check wiring. Replace if necessary. | Details |
| n042 | Problem with refrigerant gas sensor. Show causes & actionsLikely causes
Engineer action Check wiring. Replace if necessary. | Details |
| n051 | Boiler locked out of system Show causes & actionsLikely causes
Engineer action Check for boiler malfunction. | Details |
| n052 | Error with OpenTherm connection to boiler. Show causes & actionsLikely causes
Engineer action Check wiring. Replace if necessary. | Details |
| n053 | Flow temperature from boiler is too low Show causes & actionsLikely causes
Engineer action Set the flow temperature of the boiler at least 10ºC higher then the system flow temperature of the Xtend (P194). | Details |
| n054 | Boiler not responding to heating request from Xtend. Show causes & actionsLikely causes
Engineer action Check whether the boiler or CH function is turned off. | Details |
| n055 | Boiler has a notification Show causes & actionsLikely causes
Engineer action Resolve the Intergas boiler malfunction. | Details |
| n056 | Boiler supplies too hot water during a heating demand. Show causes & actionsLikely causes
Engineer action Check the set flow temperature of the boiler. Check the set power of the boiler | Details |
| n060 | Thermostat firmware version is not up to date if using the Intergas Comfort Touch. Show causes & actionsLikely causes
Engineer action Install the latest version of Intergas Comfort Touch. | Details |
| n070 | Heatpump error (indor unit control) Show causes & actionsLikely causes
Engineer action Check the Wifi control screen for additional information Consult Intergas Heating Ltd. | Details |
| n071 | Flow error during Heatpump operation Show causes & actionsLikely causes
Engineer action Check the flow or the system water needs refilling or topping up. | Details |
| n072 | Flow error during defrost mode Show causes & actionsLikely causes
Engineer action Check the flow or the system water needs refilling or topping up. | Details |
| n073 | Refrigerant temperature too low during defrost mode. Show causes & actionsLikely causes
Engineer action Check the refrigerant circuit for leaks. Possible refrigerant shortage. | Details |
| n074 | Defrost mode stopped due to a water temperature that is too low. Show causes & actionsLikely causes
Engineer action Check the flow Possibly low water volume | Details |
| n080 | Problem with the user interface. Show causes & actionsLikely causes
Engineer action Restart the Xtend Consult Intergas Heating Ltd. | Details |
Patterns that group across the manufacturer's fault-code table. Each entry links to the full code listing further down the page.
Engineer: Check the CH pump. Check the system for leaks. Check the system water pressure.
Triggered by fault code F001.
Engineer: Check the flow in the system.
Triggered by fault code F003.
Engineer: Reset the control unit. Replace the control unit.
Triggered by fault code F009.
Common questions from engineers and homeowners about the Intergas Xtend 5 mono FT.
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Specifications on this page are extracted from the manufacturer brochure. Always cross-check against the latest datasheet before commissioning or quoting. Last updated 30 April 2026.
Engineer: CH flow too low. Check system flow.
Triggered by fault code F010.
Engineer: Consult Intergas Heating Ltd.
Triggered by fault code F018.