Rotex RKHBH008AA User Manual (English)

Questions and Answers:

N
Nicholas James MDAug 2, 2025
What to do if Rotex RKHBH008AA Heat Pump is not heating or cooling as expected?
- D
  Dana Carter MDAug 2, 2025
  If your Rotex Heat Pump isn't heating or cooling as expected, it might be due to several reasons. First, ensure the backup heater power supply is correct, the thermal fuse is closed, the thermal protector isn't activated, and the contactors aren't broken. Also, check that the benefit kWh rate power supply settings and electrical connections match the wiring instructions. If the electricity company sent a benefit kWh rate signal, simply wait for the power to return to normal.
M
Melissa WrightAug 8, 2025
Why is the compressor not starting on my Rotex Heat Pump?
- M
  Michael GonzalezAug 8, 2025
  If your Rotex Heat Pump compressor isn't starting for space or domestic water heating, there are a few things to check. First, ensure the temperature setting on the controller is correct. Next, verify that all shut-off valves in the water circuit are fully open and that the water filter is clean. Also, ensure there is no air in the system by purging it, and check that the water pressure is adequate (greater than 0.3 bar when cold, much greater when hot). Confirm the pump speed setting is at its highest, the expansion vessel isn't broken and the water volume in the installation is above the minimum required value.
G
Gregory BushAug 14, 2025
How to fix space heating capacity shortage at low outdoor temperatures in Rotex RKHBH008AA Heat Pump?
- M
  Michael TuckerAug 14, 2025
  If you are experiencing a space heating capacity shortage with your Rotex Heat Pump at low outdoor temperatures, there are several things to investigate. First, check that the 'backup heater operation status' is turned on. Also, check whether the thermal protector and thermal fuse of the backup heater are working correctly. Ensure that the 'equilibrium temperature' is set appropriately to activate the backup heater at a suitable outdoor temperature. Finally, verify that the 'space heating priority status' is enabled and the 'space heating priority temperature' is configured correctly to prioritize space heating over domestic hot water heating.
R
Richard SmithAug 20, 2025
Why does the water pressure relief valve open on my Rotex Heat Pump?
- S
  Susan BarnesAug 20, 2025
  If the water pressure relief valve on your Rotex Heat Pump is opening, it could be due to a broken expansion vessel. In this case, replace the expansion vessel. Alternatively, the water volume in the installation might be too high. Ensure that the water volume is below the maximum allowed value.
K
Kiara FrankAug 27, 2025
How to stop Rotex Heat Pump pump from making noise?
- A
  Ashley CohenAug 27, 2025
  If your Rotex Heat Pump pump is making noise (cavitation), it could be due to air in the system. Try purging the air from the system. Another possible cause is low water pressure at the pump inlet. Check the manometer to ensure sufficient water pressure (greater than 0.3 bar when the water is cold, and much greater when the water is hot). Also, check that the manometer is not broken, the expansion vessel is not broken, and the pre-pressure setting of the expansion vessel is correct.

Rotex RKHBH008AA Specifications

General

Brand	Rotex
Model	RKHBH008AA
Category	Heat Pump
Language	English

Summary

Introduction and Scope

General Information

Provides an overview of the Rotex indoor unit and its compatibility with RRHQ heat pumps.

Scope of this Manual

Outlines the procedures covered in the installation manual for RKHBH/X indoor units.

Model Identification and Accessories

Indoor Unit Model Coding

Explains the coding system for identifying Rotex indoor unit models.

Drain Pan Kit (Optional)

Details the optional drain pan kit required for RKHBX models.

Supplied Accessories

Lists the standard accessories provided with the indoor unit.

Typical Application Examples

Application 1: Space Heating with Thermostat

Illustrates space heating only with a room thermostat connected to the indoor unit.

Application 2: Space Heating and DHW

Illustrates space heating with domestic hot water, without a room thermostat.

Domestic Water Heating and System Operation

Pump Operation and Space Heating/Cooling

Explains pump operation and system control for heating/cooling based on thermostat input.

Application 3: Cooling/Heating with Thermostat

Details an application with a room thermostat for cooling/heating changeover.

Overview of the Indoor Unit

Accessing Unit Components

Describes how to access the unit's internal components and user interface.

Pump Operation Without Thermostat

Explains how the pump operates when no room thermostat is connected.

Main Components

Indoor Unit Component Descriptions

Provides detailed descriptions of each numbered component within the indoor unit.

Switch Box and Functional Diagram

Switch Box Component Descriptions

Lists and describes the main electrical components within the switch box.

System Functional Diagram

Shows the interconnection of major system components in a schematic diagram.

Indoor Unit Installation

Selecting an Installation Location

Specifies criteria for choosing a suitable indoor installation location.

Unit Handling and Unpacking

Provides instructions for safely unpacking and handling the indoor unit.

Mounting and Pipework Installation

Mounting the Indoor Unit

Details the steps for securely mounting the indoor unit onto the wall bracket.

Drain Pan Kit Installation

Instructions for installing the optional drain pan kit for cooling models.

Refrigerant Pipework Specifications

Specifies the gas and liquid pipe connection sizes for indoor and outdoor units.

Water Circuit Checks

Outlines checks for the water circuit, including pressure and shut-off valves.

Water Volume and Expansion Vessel Setup

Calculating Expansion Vessel Pre-pressure

Explains how to calculate the correct expansion vessel pre-pressure based on height difference.

Checking Maximum Water Volume

Details how to determine and verify the maximum water volume in the system.

Water Circuit Connections and Water Filling

Connecting the Water Circuit

Provides essential guidelines for connecting the water circuit to prevent damage and ensure proper function.

Charging Water Procedure

Step-by-step instructions for filling the unit with water and purging air.

Piping Insulation Requirements

Specifies requirements for insulating water circuit piping to prevent condensation.

Field Wiring Precautions

Highlights essential safety precautions and requirements for field wiring.

System Wiring Overview

Field Wiring Diagram Illustration

Illustrates the required field wiring connections between system components.

Internal Wiring Parts Table

Lists and explains the abbreviations for internal wiring components.

Power and Thermostat Connections

Indoor Unit Power and Communication Cable

Details the power supply and communication cable requirements for the indoor unit.

Backup Heater Power Supply

Outlines the dedicated power circuit requirements for the backup heater.

Thermostat Connection Requirements

Specifies power supply and contact voltage requirements for thermostats.

Valve Control and Benefit kWh Rate Connection

Wiring Control Valves

Provides wiring instructions for 2-way and 3-way control valves.

Benefit kWh Rate Power Supply Connection

Explains how to connect to electricity company benefit rate power supply systems.

Start-up and Configuration

DIP Switch Settings Overview

Describes the DIP switch settings for configuring unit functions.

Room Thermostat Configuration

Explains how to configure the unit when a room thermostat is connected.

Configuration Details

Pump Operation Configuration

Details pump operation settings with or without a room thermostat.

Domestic Hot Water Tank Configuration

Describes the DIP switch setting for domestic hot water tank installation.

Initial Start-up at Low Temperatures

Advises on gradual heating to prevent floor cracking during initial start-up.

Pre-Operation Checks and Settings

Checks Before Initial Start-up

Lists essential checks to perform before powering on the unit.

Powering Up the Indoor Unit

Describes the initial power-up sequence and user interface display.

Setting the Pump Speed

Explains how to adjust the pump speed based on system flow.

Introduction to Field Settings

Introduces the concept of field settings for unit configuration.

Detailed Field Setting Descriptions

User Permission Level Settings

Explains how to set user permission levels for the interface.

Weather Dependent Set Point

Details settings for automatic temperature adjustment based on outdoor conditions.

Field Settings: Disinfection, Auto Restart, Backup Heater

Disinfection Function Settings

Describes settings for disinfecting the domestic hot water tank.

Auto Restart Function Settings

Explains the auto restart function after power loss.

Backup Heater and Space Heating Off Temperature

Covers backup heater operation and space heating shut-off temperature settings.

Field Settings: Temperature Priorities

Equilibrium Temperature Settings

Explains settings for restricting backup heater operation to low outdoor temperatures.

Space Heating Priority Settings

Details settings for prioritizing space heating over domestic hot water.

DT for Domestic Water Heating

Defines temperature differences for starting/stopping domestic water heating.

Field Settings: Hot Water Timers and Set Points

Domestic Hot Water Step Length

Sets temperature difference for booster heater shut-off to prevent chattering.

Domestic Water Heating Mode Timer

Configures minimum/maximum heating times and anti-recycling time.

Cooling and Heating Set Point Ranges

Defines limits for heating and cooling set points to prevent incorrect selection.

Field Settings Table

Field Settings Summary

Provides a table of all field settings, default values, and ranges.

Field Settings: Benefit kWh Rate and Unit Info

Benefit kWh Rate Power Supply Settings

Defines which heaters are switched off based on benefit kWh rate signals.

Unit Information Readout

Describes how to read software version, EEPROM, model ID, and temperatures.

Test Run, Final Check, and Maintenance

Automatic Test Run Procedure

Explains the automatic test run performed upon initial operation.

Manual Test Run Operation

Details how to manually perform test runs for heating, cooling, and DHW.

Final Installation Checks

Lists final checks to be performed after installation settings are complete.

Routine Maintenance Schedule

Lists checks and inspections to be performed annually for optimal unit availability.

Troubleshooting Guide

General Troubleshooting Guidelines

Provides general advice and precautions before troubleshooting.

Common Unit Symptoms and Solutions

Lists common unit symptoms and their possible causes and corrective actions.

Error Codes and Specific Troubleshooting

List of Error Codes and Corrective Actions

Details error codes, their causes, and corrective actions.

Specific Troubleshooting Scenarios

Space Heating Capacity Shortage

Addresses low space heating capacity at low outdoor temperatures.

Technical Specifications

General Unit Specifications

Lists general technical data including capacity, dimensions, weight, and connections.

Electrical Specifications

Provides electrical data for the standard unit and backup heater.

Troubleshooting Error Codes

Detailed Error Code Descriptions

Continues listing error codes and their corrective actions.