About the Role
:
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:
1. Install, service, and maintain commercial gas appliances and plant
2. Diagnose and repair faults on commercial boilers and associated systems
3. Maintain and repair commercial gas pipework and valves
4. Carry out combustion analysis and performance testing
5. Ensure compliance with Gas Safety (Installation & Use) Regulations
6. Complete commercial gas safety checks and documentation
7. Service, maintain, and fault‑find Heating Interface Units
8. Diagnose heating and hot water issues relating to HIUs
9. Balance, commission, and pressure‑test HIU systems
10. Liaise with heat network operators and building management systems (BMS)
11. Carry out HIU replacements and upgrades where required
12. Carry out planned maintenance on CHP units
13. Diagnose and repair CHP mechanical and control faults
14. Monitor system efficiency and thermal output
15. Work with electrical and control specialists where required
16. Ensure CHP systems operate safely and efficiently within plant rooms
17. Maintain and fault‑find Air Source Heat Pumps (ASHPs)
18. Understand integration of ASHPs with commercial heating systems
19. Support hybrid systems (gas + renewable technologies)
20. Monitor system performance and efficiency
21. Work safely in commercial plant rooms
22. Maintain pumps, pressurisation units, valves, and expansion vessels
23. Support commissioning and refurbishment projects
24. Identify defects and recommend remedial works
25. Participate in call‑out rota where applicable
26. Ensure all works comply with legislation, standards, and best practice
27. Complete job sheets, service records, and compliance documentation
28. Follow health & safety procedures, RAMS, and permit‑to‑work systems
29. Liaise professionally with clients, facilities teams, and managers
Role Criteria:
30. City & Guilds or NVQ Level 3 in Gas Installation and Maintenance
31. Valid ACS core qualifications, CCN1, CENWAT
32. CIGA1, CIGA2, CIGA3, ICPN1, CDGA1
33. DAH, (desirable)
34. CHP manufacturer training or certification – Desirable
35. HIU manufacturer training (e.g. SAV, Heatweb, Danfoss, Altecnic) (desirable)
36. LCL Awards / BPEC – Heat Networks & HIUs (desirable)
37. ASHP qualification (e.g. LCL / City & Guilds / manufacturer training) (desirable)
38. G3 Unvented Hot Water (desirable)
39. Strong experience in commercial heating environments
40. Good understanding of district heating / heat networks
41. Proven knowledge of CHP and low‑carbon systems
42. Ability to fault‑find complex heating and control issues
43. Comfortable working independently and as part of a wider technical team
44. Flexible and willing to travel across properties and support out‑of‑hours requirements
45. Full UK driving licence
Benefits we can offer you:
46. 25 days annual leave plus bank holidays
47. Annual Mears Fun Day - Our annual Fun Day is organised as a massive thank you from the Executive team for all the hard work!
48. Volunteering Leave - Mears supports employees to undertake paid volunteering in the community, in support of our social value commitment.
49. Staff perks with Mears Rewards - discounts of up to 10% weekly groceries, holidays, eye test vouchers, Share save scheme, plus much more
50. Family friendly policies
51. Company Vehicle and Fuel Card
52. 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.