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Instructions for fitting a new door seal kit when the burner door is removed during gas valve replacement.
Checks after part replacement, including flue system, seals, electrical, gas, water connections, and system pressure.
Requirements for personnel and equipment to perform combustion analysis and interpret results, referencing BS standards.
Procedure for adjusting LPG models, including steps for troubleshooting ignition lockouts (F1) by adjusting the throttle.
Procedures for checking CO2, CO/CO2 ratio, gas inlet pressure, and gas rate after adjustments.
Steps for unachieved results, repeat servicing, and seeking technical advice.
Tables detailing CO2 settings, throttle turns, CO/CO2 ratios, and maximum gas rates for Natural Gas and LPG models.
This document outlines the procedures for replacing and setting the gas valve (Dungs) in Glow-worm boilers, superseding any previous instructions found in the original appliance literature. It emphasizes the importance of safety, competency, and adherence to specific steps to ensure correct operation and compliance with regulations.
The primary function of this manual is to guide a competent person through the safe and effective replacement and adjustment of the gas valve in various Glow-worm boiler models. The gas valve is a critical component that controls the flow of gas to the burner, directly impacting the boiler's combustion performance and overall safety. The instructions detail how to achieve the correct CO2 settings for both natural gas (G20) and propane (G31) models, ensuring the boiler operates efficiently and within safe emission limits. It also covers checks for gas inlet pressure and gas rates, which are essential for verifying the proper functioning of the gas supply system. The document highlights that these procedures are crucial for maintaining the appliance's safety and performance specifications, and that any deviation or use of unauthorized parts is strictly prohibited.
The manual provides a structured approach to gas valve replacement and adjustment, starting with essential safety precautions. Before any work commences, the boiler must be isolated from both electrical and gas supplies. It stresses the use of only genuine Glow-worm spare parts to ensure compatibility and compliance with safety standards. The document includes specific kit part numbers for different boiler models, such as the 24 & 30 ultracom cx/cxi, 18 & 30 ultracom sxi/sxi, 24 & 30cxi, 12-30 hxi/ultracom hxi, 38 hxi/ultracom hxi/BG330, 38 cxi/ultracom cxi/Xtramax HE, each with distinct scroll sizes (6mm or 12mm) and accompanying components like brass flange adaptors, screws, and O-rings.
A key usage feature is the detailed guidance on adjusting the CO2 levels for both maximum and minimum rates. For maximum rate adjustment, the throttle screw (anti-clockwise to increase) is used, with a recommended 1/8 of a turn adjustment followed by a 1-minute stabilization period before re-checking. For minimum rate adjustment, the offset adjustment (anti-clockwise to decrease) is utilized, with similar small adjustments (not more than 1% of a turn) and stabilization time. These precise adjustment methods are critical for achieving the specified CO2 settings and maintaining safe combustion.
The manual also addresses specific scenarios, such as what to do if the burner door is removed during replacement (a new door seal must be fitted, part no. 801635) and how to handle LPG models that fail to ignite (turn the throttle anti-clockwise 1 full turn, reset the appliance, and repeat if necessary up to 2 extra turns). It emphasizes the importance of connecting a CO2 combustion analyser to the appropriate test point, as shown in the diagrams, to accurately measure combustion performance.
Maintenance features are integrated throughout the document, focusing on ensuring the boiler's long-term safety and efficiency after gas valve replacement. Post-replacement, a series of checks are mandatory:
The document highlights the legal requirement for any replacement parts to be carried out by a competent person approved by the Health and Safety Executive. It also stresses the importance of re-checking CO2 values and the CO/CO2 combustion ratio to ensure they remain within the specified limits. If the CO/CO2 setting exceeds the table's value, a complete servicing of the appliance is necessary.
For combustion performance, the manual refers to BS 6798: 2009, which advises that the person performing combustion measurements must be assessed as competent in using a flue gas analyser that meets BS7927 or BS-EN50379-3 requirements and is calibrated accordingly. Competence can be demonstrated by satisfactory completion of the CPA1 ACS assessment. The CO/CO2 ratio must not exceed the value shown in the table, as this is a key indicator of safe combustion.
In cases where the required combustion or gas rates cannot be achieved, the manual advises a full service of the appliance and a repeat of the combustion check procedure. If issues persist after servicing and remedial work, the appliance must be disconnected until the CO/CO2 ratio is acceptable, and advice can be sought from the Glow-worm Technical Helpline. This comprehensive approach to post-replacement checks and ongoing verification ensures that the boiler continues to operate safely and efficiently, minimizing risks and maximizing its lifespan.
General| Mounting | Wall-mounted |
|---|---|
| Output Rating | 24 kW |
| Fuel Type | Natural Gas |
| ERP Rating | A |
| Warranty | 2 years |
| Boiler Type | Combi |
| Heating Flow Temperature Range | 30°C - 80°C |
