Bosch heat pump error codes, often found in PDF manuals, signal system malfunctions. Understanding these codes is crucial for efficient troubleshooting and maintaining optimal heating/cooling performance.
Understanding the Importance of Error Codes
Bosch heat pump error codes, detailed in comprehensive PDF documentation, are vital diagnostic tools. They act as the system’s way of communicating specific issues, preventing guesswork and reducing troubleshooting time. Ignoring these codes can lead to escalating problems, reduced efficiency, and potentially costly repairs. A PDF manual provides a structured reference, enabling homeowners and technicians to pinpoint the exact source of a malfunction – be it electrical, refrigerant-related, or a sensor failure.
Early identification, guided by these codes, allows for proactive maintenance, extending the lifespan of the heat pump. Furthermore, understanding the error code’s meaning ensures appropriate repair strategies are employed, avoiding further damage. Accessing the Bosch PDF guides empowers informed decision-making, whether handling minor issues independently or contacting a qualified professional for complex repairs.
What is a Bosch Heat Pump?
Bosch heat pumps are highly efficient heating and cooling systems utilizing renewable energy from the air or ground. Unlike traditional furnaces, they transfer heat rather than generate it, resulting in lower energy consumption and reduced carbon footprint. Bosch offers a diverse range of heat pump models, including air-to-air, air-to-water, and geothermal systems, catering to various climates and home sizes.
These systems incorporate advanced technology, often detailed in accompanying PDF manuals, for precise temperature control and optimal performance. Understanding the intricacies of a Bosch heat pump is crucial when interpreting error codes. The PDF documentation outlines the system’s components, operational principles, and troubleshooting procedures; Properly functioning Bosch heat pumps deliver consistent comfort while minimizing energy costs, making them a sustainable choice for modern homes;

Common Bosch Heat Pump Error Codes ‒ General Categories
Bosch heat pump errors, detailed in PDF guides, generally fall into electrical, refrigerant, sensor, and communication issues, requiring specific diagnostic steps.
Electrical Errors
Bosch heat pump electrical errors, comprehensively listed in service PDF documentation, often indicate power supply problems, wiring faults, or component failures. Common codes within this category suggest issues with the compressor’s electrical connections, fan motor circuits, or the control board itself. Troubleshooting typically begins with verifying proper voltage levels and checking for blown fuses or tripped circuit breakers.
Detailed PDF manuals emphasize the importance of inspecting wiring harnesses for damage, corrosion, or loose connections. Electrical errors can also stem from malfunctioning relays, capacitors, or transformers within the heat pump system. Always prioritize safety when dealing with electrical components, disconnecting power before any inspection or repair work. Ignoring electrical faults can lead to further damage or even pose a safety hazard, necessitating professional intervention.
Refrigerant Related Errors

Bosch heat pump refrigerant errors, thoroughly detailed in system PDF guides, typically point to leaks, insufficient refrigerant charge, or issues with the refrigerant cycle components. Error codes in this category often relate to low or high refrigerant pressure readings, indicating a potential leak in the system’s tubing, connections, or evaporator/condenser coils.
PDF troubleshooting guides stress the need for a qualified technician to diagnose and repair refrigerant-related problems, as handling refrigerants requires specialized equipment and certification. Symptoms can include reduced heating or cooling capacity, ice formation on the coils, or unusual noises. Addressing refrigerant issues promptly prevents compressor damage and ensures optimal heat pump efficiency. Never attempt to recharge the system without proper training and tools.
Sensor Errors
Bosch heat pump sensor errors, comprehensively listed in the system’s PDF documentation, indicate a malfunction within the unit’s network of temperature, pressure, or flow sensors. These errors disrupt accurate system operation, leading to inefficient performance or complete shutdowns. Common codes relate to faulty outdoor, indoor, or refrigerant temperature sensors, as well as water flow sensors in hydronic systems.
PDF guides emphasize verifying sensor wiring and connections before replacement. A multimeter is often needed to test sensor resistance and confirm functionality. Incorrect sensor readings can trigger false error codes or cause the heat pump to operate outside optimal parameters. Replacing a faulty sensor usually resolves the issue, restoring accurate system control and efficiency. Always consult the manual for specific sensor testing procedures.
Communication Errors
Bosch heat pump communication errors, detailed within the system’s PDF manual, signify a breakdown in data exchange between the indoor and outdoor units, or between the heat pump and any connected controllers. These errors often manifest as a loss of control or inability to monitor system status. Common causes include faulty wiring, damaged communication cables, or issues with the printed circuit board (PCB).
The PDF guides recommend checking all wiring connections and cable integrity. Interference from other electrical devices can also disrupt communication. Specialized diagnostic tools may be required to pinpoint the source of the error. Resolving communication issues is crucial for restoring full system functionality and ensuring proper operation. A technician may need to reprogram or replace the PCB if the problem persists.

Specific Bosch Heat Pump Error Codes & Troubleshooting (Detailed)
Bosch heat pump PDF manuals list specific error codes with detailed troubleshooting steps. These guides help diagnose issues, ranging from simple fixes to professional repairs.
Error Code E1 ⎯ Low Water Pressure
Error Code E1 on a Bosch heat pump indicates insufficient water pressure within the hydronic system. This commonly arises from issues with the water supply, circulation pump, or blocked filters. Consulting the Bosch heat pump’s PDF service manual is the first step; it details specific pressure thresholds.
Troubleshooting involves verifying the water supply valve is fully open and checking for any kinks or obstructions in the water lines. Inspect the circulation pump for proper operation and ensure the system’s filter isn’t clogged, restricting water flow. Air trapped within the system can also trigger this error; bleeding the system may resolve it. If the problem persists, a pressure gauge can pinpoint the exact pressure level, aiding in diagnosis. Low pressure can lead to reduced heating capacity and potential system damage, necessitating prompt attention.
Error Code E2 ‒ High Water Pressure
Bosch heat pump Error Code E2 signifies excessively high water pressure within the hydronic circuit. This condition, detailed in the unit’s PDF service manual, can stem from a malfunctioning pressure relief valve, a faulty expansion tank, or a closed system lacking adequate expansion capacity. Ignoring this error risks component damage and system inefficiency.
Initial troubleshooting involves inspecting the pressure relief valve for proper operation – it should release excess pressure. Verify the expansion tank is adequately charged with air; a waterlogged tank cannot absorb pressure fluctuations. Check for closed valves or restrictions in the return line that could contribute to pressure buildup. A qualified technician should assess the system’s pressure settings and adjust them if necessary. Prolonged high pressure can cause leaks and compromise the heat pump’s longevity, demanding immediate attention.
Error Code E6 ⎯ Defrosting Error
Bosch heat pump Error Code E6 indicates a problem during the defrost cycle, as outlined in the system’s PDF documentation; This typically means the outdoor coil is icing up and the heat pump is unable to effectively remove the ice; Potential causes include a faulty defrost sensor, a malfunctioning defrost heater, or a problem with the reversing valve. A stuck reversing valve prevents hot refrigerant from circulating for defrosting.
Troubleshooting begins with checking the defrost sensor’s resistance; it should change with temperature. Inspect the defrost heater for continuity – a broken heater won’t melt the ice. Verify the reversing valve is switching correctly. Restricted airflow across the outdoor coil can also contribute to icing. A technician should examine the refrigerant charge and system controls. Ignoring E6 can lead to reduced heating capacity and potential compressor damage, necessitating prompt repair.
Error Code E16 ‒ Fan Motor Error
Bosch heat pump Error Code E16, detailed in the system’s PDF manual, signifies a fault with the indoor or outdoor fan motor. This could range from a stalled motor to an issue with the motor’s capacitor or wiring. The heat pump’s control board detects abnormal current draw or a lack of rotation, triggering the error. A common cause is a physically obstructed fan blade, preventing free movement.
Initial troubleshooting involves visually inspecting the fan blades for debris and ensuring they rotate freely. Check the motor capacitor for bulging or leakage, indicating failure. Use a multimeter to verify the motor windings have continuity. A faulty motor control module can also cause this error. If the motor itself is defective, replacement is usually necessary. Ignoring E16 can lead to overheating and potential damage to the compressor, requiring professional attention.
Error Code E22 ⎯ Compressor Error ‒ General
Bosch heat pump Error Code E22, as outlined in the system’s PDF documentation, represents a general compressor error. This broad code indicates a problem with the compressor’s operation, but doesn’t pinpoint the exact issue. Potential causes include low or high refrigerant levels, an overheating compressor, or a failure within the compressor’s internal components. The control board detects abnormal pressure readings or electrical characteristics.
Troubleshooting begins with checking refrigerant pressures using gauges. Verify the compressor isn’t physically overheating. Further diagnosis often requires specialized tools and knowledge to assess the compressor’s windings and electrical connections. More specific error codes (E22.1, E22.2, E22.3) provide greater detail. Addressing E22 typically necessitates a qualified HVAC technician due to the complexity and potential hazards involved with refrigerant handling and compressor repair.
Error Code E22.1 ‒ Compressor Overload Protection
Bosch heat pump Error Code E22.1, detailed in the system’s PDF manual, signifies that the compressor’s internal overload protection has been activated. This indicates the compressor motor experienced excessive heat or current draw, triggering a safety shutdown to prevent permanent damage. Common causes include restricted airflow across the condenser coil, a failing compressor motor, or excessively high discharge pressure due to refrigerant issues.
Initial troubleshooting involves inspecting the condenser coil for obstructions and ensuring proper fan operation. Checking refrigerant levels is crucial, as both low and high refrigerant can cause overload conditions. If the issue persists, the compressor itself may be failing and require replacement. This error often requires a qualified HVAC technician for diagnosis and repair, due to the complexities of compressor systems and refrigerant handling.
Error Code E22;2 ⎯ Compressor Phase Loss
Bosch heat pump Error Code E22.2, as outlined in the system’s PDF documentation, indicates a loss of one of the power phases supplying the compressor motor. This is a serious electrical issue that can quickly damage the compressor. Phase loss typically occurs due to problems with the electrical supply to the heat pump, such as a tripped breaker, a loose connection, or a faulty contactor.
Immediate troubleshooting requires verifying the incoming voltage to the unit and checking all electrical connections. A qualified electrician should inspect the breaker panel and wiring to identify and correct the phase loss. Running the compressor with a phase loss will cause overheating and eventual motor failure, making prompt attention critical. Do not attempt repairs if you are not a qualified electrician.
Error Code E22.3 ⎯ Compressor Short Circuit

Bosch heat pump Error Code E22.3, detailed in the system’s PDF service manual, signifies a short circuit within the compressor motor windings. This is a severe electrical fault demanding immediate attention, as it poses a significant safety risk and will inevitably lead to compressor failure. A short circuit occurs when insulation breaks down, allowing current to flow along an unintended path.
Troubleshooting involves a qualified technician using a multimeter to test the compressor windings for continuity to ground. A shorted winding will exhibit low resistance or a direct short. Attempting to operate the heat pump with a shorted compressor can cause further damage and potentially start a fire. Replacement of the compressor is typically required, and a thorough investigation into the cause of the short circuit is essential.
Error Code F1 ‒ Flame Sensor Error (Oil/Gas Models)
Bosch oil or gas heat pump Error Code F1, as outlined in the system’s PDF documentation, indicates a problem with the flame sensor. This sensor verifies the presence of a flame during the combustion process; if no flame is detected, the system shuts down for safety. A faulty flame sensor, dirty sensor rod, or weak flame can trigger this error.

Troubleshooting begins with visually inspecting the flame sensor for dirt or corrosion. Cleaning the sensor rod with fine steel wool can often resolve the issue. A multimeter can test the sensor’s functionality, checking for proper resistance. If the sensor is defective, it must be replaced. Additionally, verify proper gas supply and burner operation. Ignoring this error can lead to incomplete combustion and carbon monoxide buildup.
Error Code F2 ⎯ Ignition Failure (Oil/Gas Models)
Bosch heat pump Error Code F2, detailed in the system’s PDF manual for oil and gas models, signifies an ignition failure during the startup sequence. This means the burner isn’t igniting the fuel source after multiple attempts. Potential causes include a faulty igniter, a blocked burner, insufficient gas pressure, or a problem with the control board.
Initial troubleshooting involves checking the gas supply valve to ensure it’s fully open. Inspect the burner for obstructions like dust or debris. A multimeter can test the igniter’s continuity. If the igniter is defective, replacement is necessary. A qualified technician should verify gas pressure and inspect the control board for proper operation. Ignoring this error can lead to unburnt fuel accumulation and potential safety hazards.
Error Code A1 ‒ Water Flow Sensor Error
Bosch heat pump Error Code A1, as detailed in the system’s PDF documentation, indicates a malfunction with the water flow sensor. This sensor monitors the circulation of water within the hydronic system, crucial for heat transfer. A faulty sensor, wiring issue, or blockage in the water lines can trigger this error. Insufficient water flow prevents efficient heating or cooling.
Troubleshooting begins with visually inspecting the water lines for kinks or obstructions. Check the sensor’s wiring connections for looseness or corrosion. A multimeter can test the sensor’s resistance. If the sensor is defective, it requires replacement. Ensure the circulating pump is functioning correctly, as pump failure mimics a flow sensor error. Addressing this promptly prevents overheating and system damage.
Error Code A5 ⎯ Outdoor Temperature Sensor Error
Bosch heat pump Error Code A5, as outlined in the official system PDF manuals, signifies a problem with the outdoor temperature sensor. This sensor provides critical data for heat pump operation, influencing defrost cycles and overall efficiency. A faulty sensor, damaged wiring, or incorrect sensor placement can trigger this error. Inaccurate temperature readings compromise heating performance.
Initial troubleshooting involves inspecting the sensor’s wiring for breaks or corrosion. Verify the sensor is securely mounted and not exposed to direct sunlight or other heat sources. Use a multimeter to test the sensor’s resistance, comparing it to the values specified in the Bosch documentation. If the sensor fails the test, replacement is necessary. Correct operation ensures optimal heat pump function.
Error Code B1 ⎯ PCB Communication Error
Bosch heat pump Error Code B1, detailed within the system’s PDF service manuals, indicates a communication failure between the Printed Circuit Board (PCB) and other essential components. This disrupts the heat pump’s ability to function correctly, potentially halting operation entirely. Causes range from loose wiring connections to a faulty PCB or a problem with the communicating module.
Troubleshooting begins with a thorough inspection of all wiring harnesses connecting to the PCB, ensuring secure connections. Check for any signs of corrosion or damage. A Bosch technician may utilize diagnostic tools to pinpoint the source of the communication breakdown. PCB replacement might be necessary if the board itself is defective. Resolving this error restores system control.
Error Code C1 ⎯ Low Refrigerant Pressure
Bosch heat pump Error Code C1, as detailed in the system’s PDF documentation, signifies critically low refrigerant pressure within the system. This indicates a potential leak, reducing the heat pump’s heating and cooling capacity and potentially causing compressor damage. Low refrigerant levels hinder efficient heat transfer, impacting performance.
Troubleshooting requires a qualified technician to locate and repair the refrigerant leak using specialized equipment. Once the leak is sealed, the system must be evacuated and recharged with the correct type and amount of refrigerant, as specified in the Bosch manual. Ignoring this error can lead to compressor failure and costly repairs. Professional intervention is crucial for safe and effective resolution.
Error Code C2 ⎯ High Refrigerant Pressure
Bosch heat pump Error Code C2, documented within the system’s PDF service manual, indicates excessively high refrigerant pressure. This typically arises from a restriction within the refrigerant circuit, potentially caused by a blocked filter drier, kinked refrigerant lines, or a malfunctioning expansion valve. High pressure strains the compressor and other components.
Troubleshooting necessitates a qualified HVAC technician to diagnose the source of the restriction. They will utilize pressure gauges and other diagnostic tools to pinpoint the blockage. Repair may involve replacing the filter drier, straightening refrigerant lines, or replacing the expansion valve. Correct refrigerant charge is vital after repair, as outlined in the Bosch manual. Ignoring this error risks compressor failure and system damage.

Locating the Error Code Information
Bosch heat pump error codes are readily available in the official system PDF service manuals, on the unit’s display, and through online resources.
Checking the Heat Pump Display

Bosch heat pumps frequently feature a built-in display panel designed to communicate system status, including active error codes. This is often the quickest method for initial diagnostics, eliminating the immediate need to consult a PDF manual. The display will typically show a letter and number combination – the specific error code – providing a starting point for troubleshooting.
Referencing the error code list within the system’s PDF documentation is essential to decipher the meaning of the displayed code. Some models may offer a brief description directly on the display, but the manual provides more detailed explanations and recommended actions. Regularly checking the display can help identify intermittent issues before they escalate into major problems. Remember to note the code accurately before attempting any resets or repairs, as this information will be vital if professional assistance is required.
Using the Bosch Service Manual
The Bosch service manual, often available as a PDF download from the official Bosch website or supplied with the unit, is the definitive resource for understanding heat pump error codes. These manuals contain comprehensive lists detailing each code’s meaning, potential causes, and step-by-step troubleshooting procedures. Unlike brief online guides, the service manual offers in-depth technical information tailored to your specific model.
Locate your heat pump’s model number to ensure you’re referencing the correct manual. Within the PDF, search for the “Error Codes” or “Troubleshooting” section. The manual will typically categorize codes by severity and provide diagrams to aid in component identification. Always prioritize the manual’s recommendations and safety warnings when attempting repairs. Remember, attempting repairs without proper knowledge can void warranties and potentially cause further damage.
Online Resources for Bosch Error Codes
While the Bosch service manual PDF remains the primary source, several online resources can supplement your troubleshooting efforts. Numerous HVAC forums and websites dedicated to appliance repair often host discussions about specific Bosch heat pump error codes, offering user-reported solutions and insights. However, exercise caution and verify information from these sources against the official manual.
Bosch’s official website may also provide limited error code information or links to relevant support documentation. Be aware that online resources may not always be up-to-date or accurate for all models. Searching for your specific error code along with “Bosch heat pump” can yield helpful results, but always prioritize safety and consult a qualified technician when dealing with complex issues or refrigerant-related problems;

Safety Precautions When Troubleshooting
Bosch heat pump troubleshooting, referencing PDF manuals, requires caution. Disconnect power before inspection, and avoid refrigerant handling without proper certification.
Electrical Safety
Prioritize electrical safety when diagnosing Bosch heat pump issues, utilizing the PDF error code documentation. Always disconnect the main power supply to the unit at the breaker box before commencing any inspection or component testing. Confirm power is off with a reliable voltage tester.
Never work on electrical components with wet hands or while standing in damp conditions. Inspect wiring for damage – frayed insulation, loose connections, or signs of overheating – and replace any compromised wires immediately. Be mindful of capacitors, as they can retain a dangerous charge even after power is disconnected; discharge them properly before handling.
If you are uncomfortable working with electrical systems, or if the error code indicates a significant electrical fault, consult a qualified HVAC technician. Ignoring electrical safety precautions can lead to severe injury or even death.
Refrigerant Handling
Refrigerant handling requires strict adherence to safety protocols when addressing Bosch heat pump error codes detailed in the PDF manual; Refrigerant circuits are pressurized and contain substances harmful to the environment and human health. Never attempt to open refrigerant lines or disconnect components without proper training and EPA certification.
Always wear appropriate personal protective equipment, including safety glasses and gloves, when working near refrigerant lines. If a leak is suspected, ventilate the area immediately. Recover any released refrigerant using approved recovery equipment, following all local and federal regulations.
Improper refrigerant handling can result in environmental damage, fines, and personal injury. If the error code points to a refrigerant issue, it’s best to contact a certified HVAC technician for diagnosis and repair.

When to Call a Professional
Bosch heat pump PDF error code troubleshooting has limits; complex issues or refrigerant concerns necessitate a qualified HVAC technician’s expertise for safe resolution.
Complex Error Codes
When encountering intricate Bosch heat pump error codes detailed in the system’s PDF manual, professional intervention is strongly advised. These codes often indicate deeply rooted system problems beyond the scope of typical DIY repairs. Issues involving the compressor, intricate sensor networks, or PCB communication failures require specialized diagnostic tools and expertise.
Attempting self-repair on complex errors can lead to further damage, void warranties, and potentially create safety hazards. A certified HVAC technician possesses the knowledge to accurately interpret these codes, pinpoint the root cause, and implement effective solutions. They have access to updated technical bulletins and can perform precise calibrations and adjustments. Ignoring complex codes or attempting inadequate fixes can result in costly repairs down the line, making professional assistance a prudent investment.
Refrigerant Issues
Bosch heat pump error codes, as detailed in the system’s PDF documentation, frequently relate to refrigerant problems; Codes indicating low or high refrigerant pressure (like C1 or C2) signify leaks, blockages, or compressor malfunctions. Refrigerant handling requires EPA certification due to environmental regulations and safety concerns. Attempting to recharge the system without proper training and equipment is illegal and dangerous.
Low refrigerant reduces cooling/heating capacity and can damage the compressor. High pressure suggests obstructions or overcharging; Identifying and repairing leaks necessitates specialized leak detection tools. A qualified HVAC technician can safely recover, recycle, and recharge the refrigerant, ensuring optimal system performance and adherence to environmental standards. Ignoring refrigerant issues leads to system failure and potential environmental harm, making professional intervention essential.
















































































