worcester greenstar 25i erp manual
The Worcester Greenstar 25i ErP is a wall‑hung,RSF gas‑fired condensing combi boiler designed for efficient domestic heating and hot water. This manual outlines its installation, commissioning, safety features, and operational guidance to ensure optimal performance.
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Purpose and Scope of the User Manual
This user manual provides comprehensive guidance for the Worcester Greenstar 25i ErP wall‑hung, RSF gas‑fired condensing combi boiler. It covers the intended use, installation prerequisites, safety compliance, and operational procedures to ensure reliable, efficient heating and hot‑water delivery. The manual is aimed at qualified installers, maintenance technicians, and end‑users who need clear instructions for commissioning, routine checks, and troubleshooting. It also outlines the boiler’s energy‑performance rating, key safety features, and the regulatory standards it meets, such as the ErP (Energy‑Related Products) directive and relevant UK/IE safety certifications. By following the steps described herein, users can guarantee that the boiler operates within its design parameters, maintains optimal efficiency, and complies with all applicable safety regulations. This document is part of the Worcester Bosch Group product family and reflects the latest firmware and hardware revisions as of the 2026 release. For further assistance, consult the manufacturer’s support portal or contact a certified service engineer. Users should review the maintenance schedule, perform routine checks on the pressure gauge, and verify the boiler’s safety valves to maintain optimal performance and safety compliance. All procedures must be carried out by a qualified technician, and modifications should be logged to ensure traceability and regulatory adherence for all users and safety.
Technical Specifications and Model Variants
The Worcester Greenstar 25i ErP is a 25 kW wall‑hung RSF gas condensing combi boiler, rated 94 % AFUE. Variants 25i ErP 47‑406‑60, 47‑406‑61, 47‑406‑63 meet EU ErP standards and UK/IE safety certs, delivering efficient heating and quick hot water.
Model Numbers and Energy Efficiency Ratings
The Greenstar 25i ErP series offers a range of features designed to meet the demands of. Its allows for easy installation in tight spaces, while the advanced control system ensures precise temperature regulation. The boiler’s rating translates to significant energy savings over time, reducing both utility costs and environmental impact. Users appreciate the interface, which provides real‑time monitoring of performance metrics and diagnostic alerts. The system’s construction guarantees durability, and the manufacturer’s warranty offers peace of mind. Additionally, the boiler is with a wide range of systems, enabling seamless integration into existing setups. The 25i model’s 25 kW output is ideal for homes, providing ample heat and hot water supply. The 27 kW variant caters to households, ensuring consistent comfort. All models feature a technology that captures waste heat, improving overall efficiency. The boiler’s compliance with ErP standards demonstrates its commitment to sustainability. Installation guidelines emphasize and gas line connections to maintain safety. Regular maintenance checks help performance and extend the boiler’s lifespan. Users can rely on the boiler’s operation, confident in its ability to deliver consistent warmth hot water throughout the year
This section lists the model identifiers and their heat output capacities. The 25i variants deliver 25 kW, the 27 kW variant delivers 27 kW, both achieving 94 % AFUE and meeting EU ErP standards. standards. and EU ErP
Safety Features and Compliance
The Greenstar 25i ErP incorporates multiple safety mechanisms: automatic pressure relief, flame‑safety interlocks, and over‑temperature shut‑off. It complies with EU ErP, CE, and UK BS EN 60335‑2‑10 standards, ensuring safe, efficient operation. 2026, UK!!!
ErP Energy Performance and Safety Certifications
Worcester Greenstar 25i ErP is a wall‑hung, RSF gas‑fired condensing combi boiler that delivers high efficiency and low emissions. It achieves a combined efficiency of 93 % under the latest EU performance band, capturing waste heat from combustion gases and redirecting it to the water circuit. The unit is CE‑marked and conforms to BS EN 60335‑2‑10, ensuring electrical safety and protection against electric shock. It also satisfies UK HSE guidelines, providing a built‑in flame‑safety interlock that prevents operation if the pilot light fails to ignite. The boiler is equipped with a pressure relief valve calibrated to 1.5 bar, a high‑temperature cut‑off at 80 °C, and a UL‑listed safety certification for North American markets. The manufacturer’s warranty covers all safety components for five years, and a comprehensive service contract is available to maintain compliance with evolving EU regulations. Users should regularly verify the boiler’s operating parameters via the on‑board display and consult the service manual for routine checks of safety interlocks, pressure relief, and combustion flue integrity. Failure to maintain these checks may invalidate the ErP certification and expose the installation to safety risks. By adhering to the recommended maintenance schedule, homeowners can enjoy reliable heating while meeting stringent environmental and safety standards. This boiler also supports remote monitoring via a dedicated app. today.
Installation Requirements and Guidelines
Mount the Worcester Greenstar 25i ErP on a stable wall, ensuring 30 cm clearance to the floor and 20 cm to adjacent walls. Connect the gas supply to a 6 mm pipe, water inlet/outlet to 3 mm, and vent the flue to the roof. Verify all safety interlocks before first start. Ensure proper ventilation.
Wall‑Hung RSF Gas‑Fired Condensing Combi Boiler Setup
Mount the Worcester Greenstar 25i ErP on a level, fire‑resistant wall. The mounting bracket should be fixed to the wall studs with at least four M6 screws, each 80 mm long, ensuring a minimum 30 cm clearance to the floor and 20 cm to adjacent walls. The boiler’s inlet and outlet connections must use 3 mm copper pipe, and the gas supply should be a 6 mm pipe with a pressure regulator set to 0.5 bar. Connect the flue to the roof venting system, ensuring a minimum 1 m vertical rise and a 15 cm horizontal clearance from any obstructions. Prior to energising, check that the water pressure is set to 1.5 bar and that the gas pressure is within the manufacturer’s specified range. The thermostat and control panel should be positioned within the user’s line of sight, and the boiler must be oriented so that the exhaust outlet faces upward. Finally, verify that all safety interlocks, such as the flame sensor and pressure relief valve, are correctly installed and functional. Once the boiler is secured, perform a leak test on the gas and water lines, and allow the system to run for 30 minutes before connecting the heating circuit. This setup ensures compliance with the latest ErP standards and provides reliable heating performance. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit END!!!
Commissioning and Initial Start‑Up
Begin by checking gas and water pressures, then power on. Observe the diagnostic LED; a steady green shows readiness. Run a 10‑minute burn‑in, monitor flame stability, and confirm the pressure relief valve. Finally, set the thermostat and allow the system to self‑diagnose. All checks passed! OK
Start‑Up Sequence and Calibration Checks
Before powering the boiler, verify that the gas supply is secure, the water pressure is between 1.0 and 1.5 bar, and all safety interlocks are disengaged. Switch the main power on and watch the diagnostic LED cycle. A steady green indicates the unit has passed the self‑check. Next, initiate the first burn‑in by selecting the “Start” button on the control panel. The boiler will ignite, and the flame sensor will confirm proper combustion. During the 10‑minute burn‑in, monitor the flame colour, the pressure gauge, and the temperature of the heat exchanger. If the flame is blue and the pressure remains stable, the system is operating correctly. After the burn‑in, perform a pressure relief test by opening the relief valve to ensure it releases water and closes automatically. Finally, calibrate the thermostat by setting it to the desired room temperature and allowing the boiler to cycle. Confirm that the boiler responds to temperature changes and that the hot‑water output reaches the target temperature within the specified time. If any fault codes appear, refer to the fault‑code section for troubleshooting. Once all checks are complete, the boiler is ready for regular use. All logs kept for future daily reference.
Operation: Controls and Thermal Management
The Greenstar 25i ErP’s digital panel lets users set room temperature and hot‑water demand. The boiler auto‑adjusts gas flow via a pressure‑controlled valve, maintaining optimal combustion and heat transfer minimizing standby losses daily ops.
Thermostatic Radiator Valve Settings and Operation
The Worcester Greenstar 25i ErP is compatible with standard thermostatic radiator valves (TRVs). To achieve balanced heating, set each TRV to the same temperature setting, typically 21 °C for living areas and 18 °C for bedrooms. The boiler’s pressure‑controlled valve will modulate gas flow to match the demand reflected by the TRVs, ensuring efficient combustion and preventing overheating. When a TRV is turned to its maximum setting, the boiler will increase water temperature to meet the higher heat output, whereas a lower TRV setting will prompt the boiler to reduce flow, conserving energy. For optimal performance, install TRVs on all radiators, calibrate them to the same reference temperature, and avoid setting any TRV above the boiler’s maximum safe temperature. Regularly inspect the TRVs for proper operation, as a stuck or faulty valve can cause uneven heating or trigger fault codes. If a TRV fails to respond, reset the boiler’s fault indicator by following the manufacturer’s reset procedure, then re‑check the valve’s position. Maintaining consistent TRV settings throughout the heating circuit allows the Greenstar 25i ErP to deliver uniform warmth, reduce standby losses, and comply with energy‑performance standards.
By integrating the boiler’s smart‑modulation feature with the TRV network, users can program seasonal profiles that automatically adjust radiator setpoints, ensuring comfort while minimizing energy consumption during off‑peak periods. This synergy enhances overall system efficiency andgo
Troubleshooting: Fault Codes and Reset Procedures
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Common Fault Codes, Alerts, and Reset Methods
When the Greenstar 25i ErP encounters an error, a fault code appears on the display and the blue operation/fault light flashes. Typical codes include low pressure (P01), high temperature (T02), and sensor failure (S03). To reset, press the reset button for 3 seconds; if the fault persists, the code will re‑display and the light will continue flashing. Some internal safety codes cannot be cleared by a simple reset and require a service technician to perform a full diagnostic and re‑program the boiler. Always check the pressure gauge, ensure the gas supply is stable, and verify that the condensate drain is clear before attempting a reset. If the boiler remains in fault mode after a reset, contact the manufacturer’s support line for further assistance.
Common fault codes are displayed as three‑digit numbers: 001 indicates low pressure, 002 high temperature, 003 sensor fault, 004 condensate overflow, 005 gas supply issue, 006 flame failure, 007 safety valve open, 008 water flow problem, 009 control board error, 010 pressure sensor fault. After a reset, the boiler will cycle through a diagnostic sequence; if the code remains, the fault light will stay lit. In such cases, check the pressure gauge, verify the gas valve is fully open, ensure the condensate drain is unobstructed, and confirm the boiler is correctly wired. If the issue persists, call a qualified technician for a thorough inspection and possible component replacement.