Domestic gas meter industry

Formerly SIM 05/2005/08 - Changes in the gas metering industry


This replaces SIM 05/2005/08. It explains work in the domestic gas metering industry, highlights safety issues, explains the 'Smart' meters installation programme and guides inspectors on investigating incidents involving gas meters.


The gas industry regulator Office of Gas and Electricity Markets (Ofgem) published proposals in 2000 to secure effective competition in the provision of gas metering services previously carried out by the gas transporter, at that time Transco. HSE, Ofgem and the industry worked together to ensure that technical and safety issues were addressed. At HSE's request, Ofgem arranged for a formal risk assessment to determine whether the proposals gave rise to additional risks and how they should be controlled.

The key responsibilities for meter provision lie with the Meter Asset Manager (MAM). This is the company with whom a gas supplier or gas transporter contracts to provide metering services to customers and is responsible for the meter at all stages of it's life ('cradle to grave').  An outcome of the Ofgem work was production of a code of practice for gas meter asset managers known as MAMCOP. Ofgem amended gas suppliers' and transporters' licence conditions to require them to use MAMs who comply with the MAMCOP and transporters now have arrangements in place to authorise MAMs to carry out metering work.

MAMs are required to register with Ofgem and Lloyds Register is appointed to assess and audit compliance with the MAMCOP.  There is a list of current MAMs (of which there are 33 as of December 2013) on the Lloyds Register website.

Meter installation, including installation/replacement of regulators is carried out by one of many companies who are contracted to do this on behalf of the MAMs.  Approved Meter Installers (OAMIs), work to agreed Codes of Practice linked to MAMCOP.

In some cases, the roles of transporter, MAM and OAMI are carried out by divisions of the same company eg National Grid Gas/National Grid Metering and National Grid still owns the largest proportion of meters still in use.

A list of OAMIs, of which there are 113 as of June 2013, is on the Ofgem site.

Note: The 'transporter', often known as the 'conveyor' is the organisation which owns the gas service pipes and the 'supplier' is the organisation which supplies gas to consumers and bills them.


Dangerous gas fitting reports, including gas meter issues, should be investigated in accordance with the current selection criteria.  Reports of accidents to meter engineers removing, installing or carrying out any subsequent work on meters should also be selected for investigation in accordance with the current criteria.

Any issues identified or investigated relating to the roll-out programme for smart meter installation (whether or not this is a gas safety issue), should be brought to the attention of the Sector (MTU Utilities section).

Inspectors should see Appendices 1 and 2 for important technical information that they need to be aware of.


In 2012 Governance of MAMCOP was passed from Ofgem to Supply Point Administration Agreement (SPAA), with the aim of providing improved coordination between suppliers and transporters.  SPAA specifies the operating arrangements with which all the UK domestic gas suppliers and transporters must comply under the terms of their licenses.  As was previously the case, HSE has representation on the Management Board.


Recording & Reporting

Make clear in COIN reports that the issue relates to 'gas meters' or, where relevant, 'gas smart meters'.


OPSTD MTU, Utilities section.

Appendix 1:  Meter work and pressure regulators

Meter installation includes the regulator, the means by which pressure in the downstream system is controlled. It is essential that gas appliances operate at the correct pressure to ensure safe gas combustion. Overpressure can lead to incomplete gas combustion and the production of carbon monoxide so the regulator. So the regulator is a vital safety component which needs to be 'matched' to the meter and incoming gas supply pressure.

Recent developments include an increased use of medium pressure gas supplies to domestic premises. Low pressure operates at less than 75 mbar and medium pressure  between 75 mbar and 2 bar. Different pressure control arrangements and additional competences are required for medium pressure work.  In some rural areas of Scotland and Wales there are also Intermediate Pressure supplies which operate between 2 and 7 bar.

Standards bodies such as British Standards and the Institution of Gas Engineers and Managers (IGEM) have translated old British Gas and Transco procedures into industry wide standards. For domestic work there are specific competencies under the Nationally Accredited Certification Scheme (ACS) for low and medium pressure metering work, though none presently exist for intermediate pressure.

Gas engineers replacing meters will undertake a limited range of duties, ie isolate the supply, replace the meter and regulator, purge and relight gas appliances and tightness test the installation. Although they will not have specific appliance competences, their core training enables them to identify most visual defects on appliances and apply the Gas Industry Unsafe Situations Procedure (GIUSP) to appliances that are 'Immediately Dangerous' or 'At Risk'.

Contractorising metering provision has highlighted issues about the safety of external low pressure meter boxes, often provided to facilitate meter reading.  Specifically:

  • Installation faults including lack of sleeving for gas pipework passing through the cavity wall into the property, and damage to the box structure. Industry procedures have been reinforced to ensure these defects are addressed when found.
  • Some external meter boxes are prone to vandalism allowing access to the Emergency Control Valve (ECV).  The Gas Safety (Installation and Use) Regulations 1998 (GSIUR) do not address this issue and responsibility for rectifying the situation, which may include resiting the meter, will generally rest with the building owner. The gas transporter and/or the gas supplier/meter owner (if different) may also have a role. In practice, the MAM will make arrangements to mend locks/meter boxes where damage is minor and any further work would have to be agreed between the parties involved.

Gas suppliers are required to carry out safety inspections on meters.  This is presently every 2 years, although this frequency is under review and likely to move towards a risk-based regime.   MAMs will carry this out on behalf of the suppliers.

Consumers need to have ready access to the emergency control valve (ECV).  For consumers in multi-occupancy buildings, there may be: individual meters with an ECV at each dwelling; banks of individual meters with remote ECVs but with additional emergency control valves (AECVs) at each dwelling; or a bulk meter with a remote ECV and an AECV at each dwelling. 

ECVs are not 'gas fittings' as defined so work on the ECV is not 'gas work' as GSIUR does not apply.  Isolating the gas supply and disconnecting the meter and capping off the pipework at the ECV outlet are also not 'gas work' and do not require engineers to be Gas Safe registered.

Appendix 2:  Smart meters

'Smart' meters can be monitored remotely by the supplier. This allows accurate billing without the need for the site visits to read the meter (although periodic safety inspections will still be required) and gives the consumer real-time gas usage readings.

As part of a government initiative on energy efficiency, Department of Energy and Climate Change (DECC) is taking forward a supplier-led  programme to replace most traditional ('dumb') meters with 'smart' meters. Further information is at Smart meters: a guide.

The 'foundation phase' runs until autumn 2015 during which time many dumb meters that need changing will be replaced by the smart version. The main 'roll out' phase of replacement runs from autumn 2015 to 2020.  It is estimated that over 50 million gas and electricity meters will be replaced in 30 million households and small businesses.  To facilitate the scale of this task, existing engineers are being upskilled for smart meter installation and a large number new to the industry are being recruited and trained in limited scope work ie they will have ACS only for meter installation.  It is estimated that at least 7000 engineers will be carrying out installation work and many will have the competencies to install both electric and gas meters for dual-fuel customers.  Agreed nationally accredited training and assessment criteria have been developed under the auspices of the National Skills Academy for Power (NSAP).

While not specific to smart meter installations, the sheer number of meter replacements and 'new entrants' mean that potential risks to engineers and consumers need to be considered as part of the programme. Hazards such as co-location of electrical installations, presence of asbestos at meter positions, means of access, lone working, provision and use of appropriate PPE and possible abuse from customers have been identified and the programme is working to control these risks. HSE participates in the operational issues sub-group, NSAP group and has contributed to the industry group on asbestos. Reports of incidents and 'near misses' are being monitored both by the Sector and relevant employers.

Meters should conform to the Smart Meter Technical Specification (SMETS) in addition to relevant standards and be installed in line with industry procedures and codes including MAMCOP.  Ofgem has introduced a new code of practice, Smart Metering Installation Code of Practice (SMICOP) in June 2013, to run alongside MAMCOP and with which all installers need to comply.  This Code sets out rules and standards of conduct for suppliers installing smart meters, eg rules of sales and marketing at installation and requirements around raising consumer awareness.

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Updated 2022-02-04