Commercial Gas Engineer

About the Role

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The Commercial Gas Engineer is responsible for the installation, maintenance, fault diagnosis, and repair of commercial gas‑fired systems and associated plant across commercial and residential‑scale properties. The role requires strong working knowledge of commercial heating systems, including CHP units, HIUs, and low‑carbon technologies such as Air Source Heat Pumps.

Duties:

Install, service, and maintain commercial gas appliances and plant

Diagnose and repair faults on commercial boilers and associated systems

Maintain and repair commercial gas pipework and valves

Carry out combustion analysis and performance testing

Ensure compliance with Gas Safety (Installation & Use) Regulations

Complete commercial gas safety checks and documentation

Service, maintain, and fault‑find Heating Interface Units

Diagnose heating and hot water issues relating to HIUs

Balance, commission, and pressure‑test HIU systems

Liaise with heat network operators and building management systems (BMS)

Carry out HIU replacements and upgrades where required

Carry out planned maintenance on CHP units

Diagnose and repair CHP mechanical and control faults

Monitor system efficiency and thermal output

Work with electrical and control specialists where required

Ensure CHP systems operate safely and efficiently within plant rooms

Maintain and fault‑find Air Source Heat Pumps (ASHPs)

Understand integration of ASHPs with commercial heating systems

Support hybrid systems (gas + renewable technologies)

Monitor system performance and efficiency

Work safely in commercial plant rooms

Maintain pumps, pressurisation units, valves, and expansion vessels

Support commissioning and refurbishment projects

Identify defects and recommend remedial works

Participate in call‑out rota where applicable

Ensure all works comply with legislation, standards, and best practice

Complete job sheets, service records, and compliance documentation

Follow health & safety procedures, RAMS, and permit‑to‑work systems

Liaise professionally with clients, facilities teams, and managers

Role Criteria:

City & Guilds or NVQ Level 3 in Gas Installation and Maintenance

Valid ACS core qualifications, CCN1, CENWAT

CIGA1, CIGA2, CIGA3, ICPN1, CDGA1

DAH, (desirable)

CHP manufacturer training or certification – Desirable

HIU manufacturer training (e.g. SAV, Heatweb, Danfoss, Altecnic) (desirable)

LCL Awards / BPEC – Heat Networks & HIUs (desirable)

ASHP qualification (e.g. LCL / City & Guilds / manufacturer training) (desirable)

G3 Unvented Hot Water (desirable)

Strong experience in commercial heating environments

Good understanding of district heating / heat networks

Proven knowledge of CHP and low‑carbon systems

Ability to fault‑find complex heating and control issues

Comfortable working independently and as part of a wider technical team

Flexible and willing to travel across properties and support out‑of‑hours requirements

Full UK driving licence

Benefits we can offer you:

25 days annual leave plus bank holidays

Annual Mears Fun Day - Our annual Fun Day is organised as a massive thank you from the Executive team for all the hard work!

Volunteering Leave - Mears supports employees to undertake paid volunteering in the community, in support of our social value commitment.

Staff perks with Mears Rewards - discounts of up to 10% weekly groceries, holidays, eye test vouchers, Share save scheme, plus much more

Family friendly policies

Company Vehicle and Fuel Card

Access to EAP Counselling sessions

All our roles require candidates to have the entitlement to work within the UK, Mears does not currently offer visa sponsorship.

To drive a Mears vehicle, you must be aged over 21 have held your licence over 3 months and have less than 9 points.

Candidates should be aware that all our roles are subject to relevant Background, Identity & Security checks before commencement of employment.