Alpha E‑Tec 28 Overview
The Alpha E‑Tec 28 is a wall‑mounted, fan‑assisted, room‑sealed, high‑efficiency condensing boiler delivering central heating and domestic hot water at mains pressure. It includes pump, pressure relief valve, expansion vessel, gauge, and supports Easy‑Stat or Alpha Climatic controls for optimal efficiency.!!!!
Technical Specifications
Rated 28kW output, 95% condensing efficiency, gas‑fired, 2.5kW fan, 1.5kW pump, 0.5kW expansion vessel. Dimensions 800mm x 400mm x 200mm, weight 120kg. Operating pressure 1‑1.5bar, inlet 0.5‑1.5bar, outlet 1.5‑2bar. Includes Easy‑Stat or Alpha Climatic controls. Rated for UK gas. Suitable for 1–2. Compact unit. ideal!
Model Variants and Ratings
The Alpha E‑Tec 28 series comprises two core power ratings, 28 kW and 33 kW, each engineered to deliver reliable central heating and domestic hot water at mains pressure; The 28 kW model offers a nominal output of 28 kW, a maximum of 30 kW during peak demand, and a minimum of 6 kW for low‑load operation, ensuring efficient performance across a wide range of temperatures. The 33 kW variant increases the nominal output to 33 kW, peaks at 35 kW, and drops to 7 kW during low‑load periods, making it suitable for larger homes or multi‑family units. Both models share the same sealed combustion chamber, fan‑assisted heat exchanger, and a high‑efficiency condensing gas burner, ensuring consistent performance regardless of the selected power rating. The 28 kW version is rated for a maximum input of 28 kW, a heat output of 28 kW, and a condensing efficiency of 92 % at 50 °C, while the 33 kW model achieves 93 % efficiency at the same temperature. Each boiler is supplied with a 1.5 kW electric fan, a 1.5 kW electric pump, and a 1.5 kW electric control module, allowing for straightforward installation and maintenance. Both units are compatible with natural gas or LPG, and conversion kits are available to meet local fuel regulations, ensuring flexibility for installers and owners alike. The 28 kW model is available in both 2‑stage and 3‑stage modulation options, while the 33 kW version offers only 3‑stage modulation, providing precise control over heat output. The maximum inlet temperature for the 28 kW model is 80 °C, and for the 33 kW model it is 90 °C, enabling operation and at high efficiency!
Boiler Type and Efficiency
Alpha E‑Tec 28 is a wall‑mounted, fan‑assisted, room‑sealed, gas‑fired condensing boiler that delivers both central heating and domestic hot water at mains pressure. Its core is a high‑efficiency condensing system that captures latent heat from exhaust gases, boosting overall thermal output. The boiler’s combustion chamber is designed for optimal airflow, and the integrated fan modulates to maintain a stable combustion temperature, reducing noise and improving reliability. With a rated output of 28 kW, it achieves an efficiency of up to 94 % under typical operating conditions, surpassing many conventional units. The unit incorporates a modulating gas valve that adjusts fuel flow in real time, allowing the boiler to match heating demand precisely and avoid the cycling losses associated with fixed‑output models. Additionally, the E‑Tec 28 features a sealed room installation that limits heat loss through the boiler housing, further enhancing performance. The combination of a fan‑assisted combustion process, a high‑efficiency condensing cycle, and a modulating gas valve makes the E‑Tec 28 a leading choice for modern, energy‑conscious heating systems. Its compact footprint sealed design cut installation space, ideal for small apartments retrofit projects. The fan‑assisted combustion delivers rapid heat recovery, while integrated safety controls guard against over‑pressure and low‑water conditions. Users gain from the optional Alpha Climatic manager, which adjusts setpoints based on weather data, cutting energy use today. daily.
Control and Sensor Options
The Alpha E‑Tec 28 offers a range of control and sensor options designed to optimise performance and energy efficiency. The standard control is the Easy‑Stat thermostat, which provides simple on/off operation with a 10‑degree setpoint range and a 2‑hour lockout to protect the boiler during short cycles. For users seeking greater flexibility, the optional Alpha Climatic energy manager can be installed. This system incorporates a built‑in temperature sensor and a weather‑based algorithm that adjusts the boiler setpoint in response to ambient temperature changes, potentially reducing fuel consumption by up to 15% during mild weather conditions.
External weather sensors can be connected via the 4‑wire terminal block, allowing the boiler to respond to real‑time outdoor temperature data. The control panel features a digital display, a reset button, and diagnostic LEDs that indicate fault codes.
Advanced users can integrate the boiler into a home automation system through the 4‑wire I/O interface. This interface enables remote monitoring and control via a compatible smart‑home hub, providing real‑time data on boiler status, temperature setpoints, and fault diagnostics. In addition, the boiler’s control system includes a 2‑hour lockout feature that prevents the burner from cycling too frequently, thereby extending component life. The diagnostic LEDs provide quick visual feedback on the boiler’s operating status, while the reset button allows users to clear fault codes after maintenance. The combination of Easy‑Stat, Alpha Climatic, and optional weather sensors offers a versatile control platform suitable for both standard and advanced heating systems.
It also supports a 4‑wire I/O interface integration.
Installation Instructions
Ensure the boiler is mounted on a stable wall, with adequate clearance. Connect the gas supply following local regulations, and attach the water supply lines. Wire the control panel, ensuring correct polarity. Install the fan expansion vessel, then perform a pressure test.
Site Preparation and Gas Connection
Before installing the Alpha E‑Tec 28, the installer must verify that the mounting surface is level, stable, and capable of bearing the unit’s weight. The boiler should be positioned at least one meter above the floor to allow adequate airflow and to accommodate the fan exhaust. A dedicated, well‑ventilated room is required; the enclosure must be sealed to prevent heat loss and to meet the manufacturer’s room‑sealed design specifications. The room must provide sufficient clearance for the boiler’s dimensions and for maintenance access, following the clearance diagram in the installation manual. The gas supply must be a 4‑pipe or 3‑pipe system, with a minimum line pressure of 0.5 bar for the 28 kW model. The gas pipe should be sized according to the manufacturer’s recommendations, typically 16 mm for a 4‑pipe system, and must be installed with a 90° bend at the boiler inlet to reduce pressure drop. All gas connections should be made by a licensed gas engineer, using approved fittings and a pressure test of at least 1.5 bar. The boiler’s gas valve must be installed on the low‑pressure side of the system, and a check valve should be placed upstream to prevent backflow. Install the gas isolation valve within five meters of the boiler, ensuring it is easily accessible for emergency shutdown. The valve should be mounted on a stable base and marked with a clear label. The gas pipe should be routed to avoid sharp bends, heat sources, and mechanical stress. Where the pipe passes through walls or floors, use appropriate fire‑resistant sleeves and secure it with clamps. All penetrations must be sealed with suitable gaskets to maintain the room‑sealed environment. After the gas line is installed, perform a leak test using a soapy water solution or a gas detector. Any bubbles indicate a leak that must be repaired before proceeding. Once the system passes the leak test, the gas supply can be turned on, and the boiler should be commissioned following the manufacturer’s commissioning procedure. This includes checking the gas pressure at the inlet, verifying the burner ignition, and confirming the correct operation of the safety valves. Finally, document the installation details, including gas pipe size, valve location, and any modifications made to the room or ventilation. This record is essential for future maintenance and for compliance with local regulations.
Electrical Wiring and Controls
Electrical wiring for the Alpha E‑Tec 28 must comply with the latest UK wiring regulations (BS 7671). The boiler is supplied with a 3‑phase, 400 V, 50 Hz connection and a 6 mm² copper cable to the main switchboard. A dedicated 32 A circuit breaker protects the unit, and a residual‑current device (RCD) of 30 mA is required for safety. The control panel is mounted on the front of the boiler and features a 2‑way selector switch, a 4‑position thermostat, and a 12‑V DC power supply for the internal electronics. Wiring must be colour‑coded: red for live, black for neutral, green/yellow for earth. All connections should be made with insulated screw terminals and tightened to the manufacturer’s torque specifications. The boiler’s fan motor is driven by a 400 V, 50 Hz induction motor with a 1.5 kW rating; it is connected through a 3‑phase contactor and a 0.5 kW overload relay. The gas valve is controlled by a 24 V DC signal from the thermostat; the valve is supplied with a 10 mm² copper cable and a 32 A circuit breaker. The control board also accepts an optional external temperature sensor; the sensor cable must be shielded and terminated with a 3‑wire connector. The entire wiring harness is routed through the boiler’s sealed cavity and secured with cable glands to prevent moisture ingress. Finally, the boiler must be connected to a 10 kW gas supply line with a pressure regulator set to 0.5 bar. All wiring work should be performed by a qualified electrician and inspected by a Gas Safe registered engineer before commissioning.
For remote monitoring, the boiler can be fitted with a 4‑wire Ethernet module. The module requires a 1 m shielded cable and a 10 Mbit/s RJ45 connector. The firmware supports MQTT and Modbus TCP/IP protocols, allowing integration with building management systems. The wiring for the Ethernet module must be routed through the boiler’s rear panel and terminated with a 2.5 mm² cable. The module’s power supply is a 12 V DC adapter, which should be mounted in the boiler’s ventilation cavity and connected via a 2 mm² cable to the control board. The Ethernet port is protected by a weather‑proof cover and must be sealed with silicone to prevent ingress of dust and moisture. All cable terminations should be inspected for continuity and insulation resistance before the boiler is powered on.
All installations must be documented and logged in the maintenance logbookCompliance.
Operation Guidelines
Operate the Alpha E‑Tec 28 by ensuring a stable gas supply, maintaining correct water pressure, and monitoring the built‑in safety valves. Use the control panel to set desired heating and hot‑water temperatures, and keep the room sealed to maximize efficiency. Always observe safety warnings. and manual.more
Starting and Shutdown Procedures
Before powering the Alpha E‑Tec 28, verify that the gas supply is open and the water line is primed. Ensure the room is well ventilated and that the boiler sits on a stable, level surface. The control panel should display a green “Ready” indicator; If an error appears, consult the fault‑code list and resolve the issue before proceeding.
To start, press the “Start” button on the panel. The electronic ignition lights the burner, and the modulating fan draws air through the heat exchanger. Within seconds the pressure gauge rises to the operating range (typically 0.5–1.0 bar). The boiler then adjusts the gas valve to maintain the set temperature. If pressure does not rise, check the water inlet for blockages and confirm the expansion vessel is charged correctly.
During operation the boiler cycles on and off to keep the room temperature within the programmed set‑point. The control system uses the room‑temperature sensor and, if connected, an external weather sensor to modulate output. Fan speed varies with heat demand, ensuring efficient combustion and minimal noise.
When shutting down, press “Stop.” The burner extinguishes and the fan slows to a halt. The pressure gauge drops to standby level. Once the boiler cools, you may safely disconnect the gas supply if the unit will not be used for an extended period. Always allow the boiler to cool to a safe temperature before performing maintenance or inspection.
For extended storage, drain the water circuit, apply an anti‑freeze agent, and cover the unit to protect it from dust and moisture. Follow the manufacturer’s guidelines for periodic checks to keep the boiler running reliably.
The boiler includes safety interlocks that prevent operation if the pressure relief valve is open, the flame sensor fails, or the fan does not run at the required speed. These interlocks trigger an alarm and shut the unit down automatically. If a fault occurs, the panel displays a fault code; refer to the troubleshooting section for resolution steps. After correcting the fault, reset the system by pressing “Reset,” then restart the boiler as described above. Keep the area around the boiler clear of combustible materials and ensure ventilation ducts are unobstructed. The E‑Tec 28 also features a built‑in condensate pump that can be switched on or off via the panel depending on local drainage conditions. If condensate drainage is not available, activate the pump to prevent water accumulation and corrosion. The pump operates automatically when the boiler reaches a temperature above 60 °C and shuts off below 45 °C. For systems with an external weather sensor, the boiler adjusts the set‑point by up to ±3 °C to compensate for ambient temperature changes, improving overall efficiency. In high‑humidity environments, monitor the condensate pump closely to avoid failure. Inspect fan blades for debris and clean them with a soft brush to maintain optimal airflow. Keep the panel and electrical connections dry and protected from dust; use a dust cover when the unit is not in use; Following these procedures ensures safe, reliable, and efficient operation of the Alpha E‑Tec 28 throughout its service life.
In case of a power outage, the boiler will automatically resume operation once power is restored, provided the gas supply remains open. The system re‑establishes pressure and temperature set‑points before resuming normal heating cycles. If the boiler fails to restart, check the main circuit breaker and ensure the panel’s battery is charged. The integrated diagnostics indicate any persistent faults. For further assistance, contact the authorized service centre or consult the online manual for detailed fault‑code explanations. Maintaining a log of all start‑up and shut‑down events helps technicians diagnose trends and pre‑empt potential failures.
Maintenance and Servicing
Check the expansion vessel, pressure gauge, and condensate pump monthly. Clean the heat exchanger, inspect fan blades, and verify the gas valve. Replace filters every 6 months. Test safety interlocks and reset fault codes. Keep the unit dry and dust‑free. All done. OK.!
Routine Inspection Checklist
- Verify the boiler is correctly mounted and secured to the wall.
- Check the pressure gauge reading when the boiler is at rest; it should be between 1.0 and 1.5 bar.
- Inspect the expansion vessel for correct pressure and ensure the bladder is intact.
- Test the pressure relief valve by gently applying pressure; it should open at the set pressure and close when released.
- Confirm the pump is running smoothly, with no unusual vibrations or noises.
- Examine the fan motor and blades for debris or damage; ensure the fan speed matches the setpoint.
- Inspect the burner flame for a steady blue color; any yellow or flickering flame indicates a problem;
- Check the gas valve for proper operation and secure connections.
- Verify the condensate drain is clear and the condensate pipe is free of blockages.
- Inspect all electrical connections for tightness and corrosion.
- Confirm the thermostat and any external sensor are correctly wired and calibrated.
- Check the safety controls, including the high‑pressure cut‑off and low‑pressure cut‑off, for proper function.
- Inspect the room‑sealed enclosure for leaks or gaps that could affect efficiency.
- Verify that the boiler’s fan‑assisted system is operating at the correct airflow rate.
- Check the boiler’s manual and any updated firmware for compliance with the latest safety standards.
- Document inspection findings, note deviations, and schedule corrective actions maintenance calendar to ensure the system longevity. !
Troubleshooting Common Issues
When the Alpha E‑Tec 28 does not start or fails to maintain heat, begin with a systematic inspection. First, confirm the gas supply: the main valve must be fully open, the meter should register a reading, and the gas pressure must fall within the specified range (typically 0.6–1.2 bar). Next, check the electrical connection: verify that the 240 V supply is stable, the circuit breaker is not tripped, and the control board displays a green status light. If the boiler fails to ignite, examine the pilot lamp for a steady glow; a flickering or absent lamp points to a faulty igniter or a blocked vent. For no heat output, inspect the expansion vessel and pressure gauge; a pressure below 1 bar on a cold start indicates a collapsed vessel or a leak in the system, while a pressure above 1.5 bar may trigger the safety relief valve and shut the boiler down. Ensure the condensate drain is clear and the condensate pump is operating; a blocked drain can cause the boiler to shut off to protect the heat exchanger. If the boiler displays error codes such as 0x01 (gas supply), 0x02 (ignition failure), or 0x03 (over‑temperature), consult the error‑code table in the manual and reset the unit by cycling the power. For intermittent operation, verify the room‑temperature sensor and any optional external weather sensor; incorrect sensor readings can cause the modulating fan to run at inappropriate speeds, leading to cycling or no output. Finally, inspect the fan motor for debris and confirm the fan blades are intact; a stalled fan prevents proper combustion air flow and triggers a safety shutdown. If all checks are normal yet the boiler remains unresponsive, contact an authorised service technician for a detailed diagnostic.
