Key Responsibilities and Required Skills for Domestic Gas Engineer

🎯 Role Definition

A Domestic Gas Engineer installs, services, maintains and repairs domestic gas appliances and central heating systems in residential properties. This role requires Gas Safe registration/ACS qualifications, excellent fault diagnosis and customer-facing skills, strict compliance with safety and regulatory standards (including CP12 Landlord Gas Safety Records), and the ability to work independently across planned service visits, reactive repairs and emergency call-outs. Ideal candidates have experience with combi, system and conventional boilers, smart heating controls, flue and gas-tightness testing, and digital job-management tools.

📈 Career Progression

Typical Career Path

Entry Point From:

Apprentice Gas Engineer / Heating Apprentice
Plumber with gas training (NVQ Level 2 Plumbing & Heating)
Heating Service Technician / HVAC Technician

Advancement To:

Senior Domestic Gas Engineer / Lead Engineer
Service Manager / Field Operations Manager
Contracts Manager / Area Manager
Technical Trainer or Gas Safety Assessor

Lateral Moves:

Commercial Gas Engineer (light commercial systems)
Renewable Heating Technician (heat pumps, hybrid systems)
Building Services Technician / Facilities Engineer

Core Responsibilities

Primary Functions

Conduct safe, compliant installation of domestic gas appliances including combi, system and conventional boilers, gas fires and cookers, following manufacturer installation instructions and Gas Safe regulations.
Complete full-scope boiler commissioning: gas tightness checks, flue and ventilation verification, burner pressure/CO testing, and ensure correct boiler settings and controls for efficient operation.
Perform routine servicing and preventative maintenance on domestic boilers and heating systems, documenting condition, remedial recommendations and parts required in service records.
Diagnose complex faults using systematic fault-finding techniques, appropriate diagnostic equipment (manometers, flue gas analyzers, multi-meters), and replace faulty components efficiently while minimizing repeat visits.
Issue and complete Landlord Gas Safety Record (CP12) certificates and ensure all mandatory safety checks are recorded in accordance with legislation and company policy.
Carry out safe repair work on gas pipework and appliances, including isolations, system flushing, pressure testing and reinstatement, ensuring leak testing and sign-off before leaving site.
Install and commission smart thermostats, room controls and programmer upgrades, ensuring customer education on operation and energy-saving features.
Manage planned maintenance schedules and service rounds, optimize route efficiency and maintain high first-time-fix rates using parts and diagnostics forecasting.
Provide clear, professional customer communication on-site: explain works to be undertaken, present safety issues, gain consent for repairs and ensure customer satisfaction on completion.
Respond to reactive and emergency call-outs, triage priority faults, make safe temporary repairs where necessary and arrange follow-ups or parts orders with urgency and clarity.
Maintain accurate, legible electronic job sheets, certificates, compliance documents and parts logs using mobile job-management apps or field management systems.
Procure, stock and manage van inventory for routine spares and consumables, identify low-stock items and liaise with parts departments to avoid delays.
Liaise with landlords, managing agents and homeowners to organise access, agree work scopes and provide professional reports and quotations for remedial recommendations.
Undertake pre-installation surveys: assess flue routes, ventilation, condensate drainage and gas supply adequacy to scope correct kit and materials.
Perform system balancing and commissioning for multi-radiator systems, including radiator venting, TRV setting and pump adjustments to optimize heating performance and efficiency.
Ensure all work meets current Building Regulations and manufacturer warranties, and escalate compliance or technical uncertainty to supervisors or technical support.
Fit and replace gas meters and meter tails in coordination with local distribution network operators where required and only where appropriately authorised and trained.
Execute safe working at height for flue terminations and external installations, using appropriate access equipment, harnesses and risk assessments.
Carry out flue height and carbon monoxide risk assessments, provide CO alarm recommendations and educate customers on CO risks and symptoms.
Participate in customer-focused improvement initiatives such as Net Promoter Score (NPS) follow-ups and remedial service drives to enhance reputation and retention.
Keep up to date with product bulletins, technical updates, Gas Safe guidance and industry best practice; attend mandatory refresher training and manufacturer courses.
Mentor apprentices and junior engineers on technical skills, best practice and compliance expectations as part of development and succession planning.

Secondary Functions

Complete daily pre-start vehicle and PPE checks and report any defects to fleet management.
Submit accurate time sheets, expenses and job close-out notes in line with company payroll and billing processes.
Support remote technical colleagues by providing on-site photos, measurements and evidence for complex warranty claims or OEM escalations.
Contribute to continuous improvement by suggesting process, parts or logistics changes to improve first-time-fix and reduce call-backs.
Assist in seasonal demand planning by providing input on spare parts consumption and common failure modes.
Participate in on-call rota arrangements where applicable, providing out-of-hours support and emergency interventions.
Attend team meetings, safety briefings and toolbox talks to reinforce health & safety standards and share learnings from incidents.
Support marketing and customer retention initiatives by agreeing service plan renewals or quoting for upgrades during visits.
Help coordinate multi-trade visits for reactive jobs that require plumbing or electrical trades, ensuring seamless customer experience.
Engage in basic administrative tasks such as filing compliance certificates, scanning documents and updating job records when required.

Required Skills & Competencies

Hard Skills (Technical)

Gas Safe registration with valid ACS qualifications (core, appliances, tightness testing) — mandatory.
Certified to complete CP12 (Landlord Gas Safety Record) and familiarity with associated documentation.
Proven experience commissioning, servicing and repairing combi, system and conventional boilers (Baxi, Worcester Bosch, Vaillant, Ideal, Viessmann, etc.).
Competent in flue testing, CO/CO2 analysis, manifold and burner adjustments, and gas pressure diagnostics.
Strong fault-finding skills across mechanical and electrical boiler components; ability to read wiring diagrams and schematic drawings.
Proficient in installing and commissioning smart thermostats, zone valves and programmer integrations.
Experience with power flushing, pump replacement, valve repairs and radiator troubleshooting.
Competent in domestic gas pipework installation, pressure testing and leak detection techniques.
Comfortable using digital job management systems, mobile documentation, and basic office software (email, spreadsheets).
Knowledge of Building Regulations (Part L, Part J where applicable) and appliance manufacturer installation standards.
Awareness and practical application of COSHH, safe isolation procedures and risk assessment techniques.
Valid UK driving licence and experience planning efficient service routes (if applicable).

Soft Skills

Outstanding customer service and the ability to explain technical issues in clear, non-technical language.
Excellent time management and prioritisation skills to balance reactive work, planned maintenance and emergency call-outs.
Strong problem-solving mindset and judgement to make safety-first decisions on-site.
High attention to detail and record-keeping accuracy for compliance and warranty purposes.
Team player with ability to mentor juniors and liaise with colleagues across departments.
Resilience and adaptability in a field-based role with variable customer environments.
Professional appearance and customer-facing demeanour; ability to build trust quickly.
Strong communication skills (verbal and written) to prepare clear reports and quotations.
Self-motivated, reliable and able to work with minimal supervision.
Commitment to continuous professional development and taking on new technical training.

Education & Experience

Educational Background

Minimum Education:

Gas Safe Registration / ACS qualifications (core modules relevant to domestic appliances).
NVQ Level 2 in Plumbing & Heating or equivalent trade qualification (City & Guilds or BTEC).

Preferred Education:

NVQ Level 3 in Plumbing & Heating or equivalent Level 3 technical qualification.
HNC or HND in Building Services / Mechanical Engineering or related field.
Manufacturer-specific training and certifications (Worcester, Vaillant, Baxi, etc.).

Relevant Fields of Study:

Plumbing & Heating
Building Services Engineering
Mechanical Engineering
HVAC / Refrigeration (useful transferable skills)

Experience Requirements

Typical Experience Range: 1–5 years of hands-on domestic gas engineering experience for mid-level roles; entry roles may accept 0–2 years with apprenticeship.

Preferred: 3+ years’ proven experience installing, servicing and repairing domestic boilers and gas appliances; demonstrable Gas Safe record, strong first-time-fix metrics and experience issuing CP12 certificates.