A heating engineer specialises in the design, installation, servicing and repair of central heating systems - including gas boilers (Gas Safe registered), oil boilers (OFTEC registered), electric heating and heat pump systems. Gas heating work requires Gas Safe registration and oil heating work requires OFTEC registration; electrical heating elements require Part P compliance. Many heating engineers hold multiple registrations. Heating system work must comply with Building Regulations Part L (energy efficiency) and, for gas systems, Part J.
What they do
- Design and install complete central heating systems
- Replace gas, oil and LPG boilers and carry out commissioning
- Install and balance radiator systems including TRVs and zone valves
- Install underfloor heating - wet (water) systems in screeds or between joists
- Carry out power flushing and system chemical treatment
- Install and commission smart heating controls (Nest, Hive, Drayton)
- Service oil boilers and issue OFTEC certificates
- Upgrade heating systems from old to new energy-efficient boilers
- Install unvented hot water cylinders (G3 qualification required)
- Convert systems between open-vented and sealed pressurised operation
When you need one
A heating engineer is needed for any work on central heating systems - from adding a single radiator to a complete system replacement.
Typical costs (UK, 2025)
| Job type | Typical cost |
|---|---|
| Hourly rate | £50 - £85 / hr |
| System power flush | £300 - £600 |
| Radiator installation (per radiator) | £150 - £350 |
| Underfloor heating system (labour, per sq m) | £15 - £35 |
| New heating system installation | £3,000 - £8,000+ |
| Oil boiler installation (labour only) | £800 - £1,500 |
A power flush is typically required when fitting a new boiler to an old system - most manufacturers require it to maintain warranty. Factor in inhibitor dosing and magnetic filter installation at the same time.
Qualifications to look for
Mandatory for any gas boiler or gas heating work. Verify at gassaferegister.co.uk before appointing.
The equivalent of Gas Safe for oil-fired heating. OFTEC engineers can self-certify oil boiler installations. Check at oftec.org.
The core vocational qualification underpinning heating system installation and service work.
Required for installation of unvented hot water cylinders. A separate qualification from Gas Safe registration and a legal requirement.
How to find a reputable heating engineer
Frequently asked questions
What is the difference between a heating engineer and a plumber?
A heating engineer specialises in central heating systems - boilers, radiators, controls and underfloor heating. A plumber focuses on water supply and drainage pipework. Many tradespeople are qualified in both; in practice the roles overlap significantly and most domestic heating engineers are also competent plumbers.
What is OFTEC?
The Oil Firing Technical Association - the trade association and competent person scheme for engineers who install and service oil-fired heating equipment. OFTEC registration is the equivalent of Gas Safe registration for oil boilers and oil-fired Aga and Rayburn range cookers. Check OFTEC registration at oftec.org.
What is a power flush?
A process using a powerful pump and chemical cleaning agents to remove sludge, rust and debris from a central heating system. Required when a new boiler is fitted to an existing system (most manufacturers insist on it as a warranty condition) or when system efficiency has declined. Typically takes 4-8 hours and costs £300-£600.