A Heating Engineer Contract is a legally binding agreement between a client and a heating engineer or heating company setting out the terms on which heating installation, servicing, or repair works will be carried out. In England and Wales, heating engineer contracts are governed primarily by the Supply of Goods and Services Act 1982 and, where the client is a consumer, the Consumer Rights Act 2015. The contract establishes the scope of work, the agreed price, the programme, the certifications and regulatory compliance obligations, and the parties' rights in relation to defects and disputes.

Heating engineering in the United Kingdom is a heavily regulated profession. Any engineer carrying out gas work — including the installation, maintenance, or repair of gas boilers, gas fires, and gas pipework — must be registered with the Gas Safe Register under the Gas Safety (Installation and Use) Regulations 1998. Working on gas appliances without Gas Safe registration is a criminal offence. A well-drafted heating engineer contract should always confirm the Gas Safe registration number of the engineer carrying out the gas work.

For new boiler installations in existing domestic properties in England, the Boiler Plus standards introduced through changes to the Building Regulations require that new boilers be condensing boilers and that certain heating controls (such as weather compensation, load compensation, or smart controls) be installed alongside the new boiler. These requirements reflect the government's commitment to improving the energy efficiency of the housing stock and reducing carbon emissions from space heating, which accounts for approximately 20% of the UK's total carbon emissions.

The heating sector is also at the forefront of the transition to low-carbon heating systems. The installation of heat pumps — both air source and ground source — is growing rapidly, driven by government incentives including the Boiler Upgrade Scheme (which provides grants of up to £7,500) and the requirement under the Heat and Buildings Strategy to phase out the installation of new gas boilers in new homes. Heat pump installers must hold F-gas qualification to handle refrigerants and should be certified by the Microgeneration Certification Scheme (MCS) to carry out installations that qualify for government grants.

A Heating Engineer Contract is distinct from a standard service agreement. It must address the specific regulatory requirements that apply to gas and heating work, including the obligation to notify certain works to the local authority building control body under the Building Regulations, the obligation to issue relevant Gas Safe certificates on completion, and — for heat pump installations — the obligation to register the installation with MCS and comply with installation standard MIS 3005.

A written Heating Engineer Contract should be put in place before any heating installation, major repair, or service work begins. There are several situations in which a formal contract is particularly important.

For new boiler installations, a written contract is essential to set out the specification of the boiler to be installed, the scope of associated works (such as new pipework, radiator upgrades, and controls), the contract price, the payment structure, and the Boiler Plus compliance obligations. Without a written contract, disputes frequently arise about whether the agreed scope of work included the replacement of specific radiators, the installation of a new magnetic filter, or the flushing of the existing pipework.

For heat pump installations, a written contract is critical for setting out the complex regulatory requirements that apply to these works, including F-gas compliance, MCS certification requirements, and the obligations relating to the Boiler Upgrade Scheme grant. The contract should make clear whether the contract price is before or after the grant has been deducted, and what happens if the grant application is rejected.

For landlords and property managers commissioning annual gas safety inspections and boiler servicing under the Gas Safety (Installation and Use) Regulations 1998, a written contract establishes a clear record of the obligation to carry out annual checks and provides evidence of compliance in the event of any regulatory investigation.

For large commercial heating projects, a written contract is essential for coordinating the heating engineer's work with other trades, setting out the programme, and managing the risk of delays and variations. A formal written contract also ensures that the engineer's obligations under CDM 2015 (the Construction (Design and Management) Regulations 2015) are clearly documented.

Finally, a written heating engineer contract is important for insurance purposes. Most professional indemnity and public liability insurance policies require that the engineer's contractual obligations are consistent with the level of cover provided, and a well-drafted contract ensures that the engineer's liability is appropriately limited.

A well-drafted Heating Engineer Contract for use in England and Wales should include several key provisions to protect both the client and the heating engineer.

The scope of works clause should clearly describe all works to be carried out, including the specific equipment to be installed (with make and model), the scope of pipework and control installation, the commissioning process, and any works to be carried out to the existing system (such as flushing or balancing). Vague descriptions such as 'install new boiler' frequently give rise to disputes about what was included.

The regulatory compliance clause should confirm the engineer's Gas Safe registration number (for any gas work) and the Competent Person Scheme under which Building Regulations notifications will be made. For heat pump installations, it should confirm F-gas certification and MCS certification details.

The Boiler Plus compliance clause (for new gas boiler installations) should confirm which Boiler Plus control measure is to be installed alongside the new boiler and should state that the installation will comply with the requirements of the Building Regulations Approved Document L.

The manufacturer warranty clause should describe the warranty applicable to the equipment installed, the registration requirements to activate the warranty, and the engineer's obligations to carry out the registration on the client's behalf.

The contract price and payment terms clause should state the agreed price, the applicable VAT rate (noting the zero-rating for heat pump installations until 2027 and the 5% reduced rate for certain other energy efficiency measures), and the payment structure. For heat pump installations under the Boiler Upgrade Scheme, the clause should explain the grant arrangement clearly.

The certificates and documentation clause should set out the engineer's obligation to provide the client with all required certificates (including the Building Regulations Compliance Certificate, Gas Safe certificate, and MCS certificate where applicable) and operating manuals on completion.

The defects liability clause should specify the workmanship warranty period and make clear that the engineer will return to remedy any defect in workmanship at no charge during that period, while making clear that manufacturer defects are subject to the manufacturer's own warranty process.