Gas Meter Replacement: Documentation & Safety

Why Meter Replacement Documentation Matters

Replacing or repositioning a gas meter isn't just a plumbing job — it's one of the most heavily regulated tasks a gas engineer can carry out. Get the documentation wrong and you're looking at enforcement action from the HSE, potential Gas Safe deregistration, and personal liability if something goes sideways.

This guide covers exactly what you need to record, which forms to complete, and how to keep your paperwork bulletproof from start to finish.

Regulatory Framework: What Governs Meter Work

Several overlapping regulations apply to gas meter replacement. The key ones you need to know are:

• Gas Safety (Installation and Use) Regulations 1998 (GSIUR) — the primary legislation covering all gas work in domestic and commercial premises
• IGEM/UP/1B — the standard for tightness testing and direct purging of small installations (up to 35mm pipe)
• IGEM/UP/1A — strength testing, tightness testing and direct purging of larger low-pressure installations
• BS 6891:2015+A1:2019 — specification for installation and maintenance of low-pressure gas pipework up to 35mm in domestic premises
• Gas Industry Unsafe Situations Procedure (GIUSP) — your classification and reporting obligations if you find defects

GSIUR requires that anyone working on a gas fitting is competent and carries out the work without creating danger, and Part C of the regulations sets specific rules for meters and regulators. Interfering with a supplier's meter without authorisation can also be an offence under the Gas Act 1986. These aren't guidelines — they're law.

Pre-Work Documentation

Site Survey and Risk Assessment

Before any spanners come out, you need a documented site survey. This should record:

• Current meter location, type, and serial number
• Proposed new meter location (if repositioning)
• Pipe run details — material, diameter, and condition of the existing installation
• Ventilation assessment for the meter housing or box
• Access requirements and any confined space considerations
• Asbestos risk — particularly in older meter cupboards and boxing

Your risk assessment must be specific to the job, not a generic template you photocopy for every call. The HSE has been clear on this: a risk assessment that doesn't reflect the actual site conditions isn't worth the paper it's printed on.

Customer Notification

The customer needs to know what the work involves, how long the gas will be off, and what the outcome will look like. Document that you've explained this. If the work involves repositioning, get written agreement on the new location before you start — disputes after the fact waste everyone's time and can leave you exposed.

Meter Bypass Procedures

When the Gas Transporter fits a bypass to allow you to work on downstream pipework while the meter is replaced, there's a specific documentation chain to follow:

1. Confirm the bypass is fitted and tested — record the GT engineer's name, the time the bypass was installed, and the result of the tightness test on the bypass itself
2. Confirm gas supply isolation — before touching any pipework, verify the supply is isolated and record the method used (ECV closure, bypass valve closure, etc.)
3. Let-by test — perform and record a let-by test on the ECV or isolation valve to confirm zero gas passage before breaking any joints
4. Purging confirmation — once the work is complete and the meter reconnected, record the purge procedure followed (IGEM/UP/1B for domestic), including confirmation of safe gas dispersal

Tightness Testing and Commissioning

After any meter replacement or repositioning, a full tightness test of the installation is mandatory. Under BS 6891 and IGEM/UP/1B, the procedure for domestic installations is:

1. Connect a suitable pressure gauge (0–60 mbar range, accurate to 0.25 mbar) to the test point
2. Turn off all appliances and pilot lights
3. Allow the pressure to stabilise for one minute
4. Monitor for two minutes — the pressure must not drop
5. If the pressure drops, locate and repair the leak, then retest

Record the gauge reading at the start and end of the test, the duration, and the pass/fail result. If you had to carry out any remedial work, document what you found and what you did to fix it.

Appliance Recommissioning

Every appliance on the installation must be checked after the meter is replaced. You need to confirm:

• Gas rate matches the data plate (within the manufacturer's tolerance — typically ±5%)
• Burner pressure is correct
• Flue performance is satisfactory (spillage test, CO/CO₂ readings)
• Safety devices operate correctly
• No gas leaks at appliance connections

This isn't optional. GSIUR Regulation 26(9) requires you to confirm the safety of the complete installation after your work, not just the bit you touched.

Handover Documentation

When the job is complete, the customer needs clear documentation of what's been done. Your handover pack should include:

• Completed job sheet — description of work carried out, materials used, meter details (old and new serial numbers)
• Tightness test certificate — with readings, duration, and result
• Appliance commissioning records — gas rate, pressures, and safety check results for each appliance
• Warning notices or labels — if any appliances were classified as AR or ID under GIUSP, the appropriate warning label must be attached and a copy included in the handover
• Gas Safe notification — confirm the work has been (or will be) notified to Gas Safe Register where required

The meter exchange details (old and new serial numbers, readings, and date) must also be passed back to the meter asset manager and supplier so industry records are updated. If you're working under a MAM's authorisation, they'll usually handle this, but confirm the process and document your part in it.

Record Retention

Keep copies of all documentation for a minimum of six years. This aligns with the limitation period for civil claims and is the standard Gas Safe auditors expect. Digital records are perfectly acceptable — in fact, they're preferred because they're searchable, timestamped, and harder to lose.

Common Compliance Pitfalls

These are the mistakes that catch gas engineers out most often on meter work:

• Skipping the let-by test — it's quick, it's easy, and it could save your life. Always test, always record it.
• Not recommissioning all appliances — if there are six appliances on the installation, you check six appliances. No shortcuts.
• Failing to record the old meter serial number — the GT needs this to close out the job properly. Write it down before it leaves site.
• Incomplete tightness test records — "Passed" isn't enough. Record the gauge, the readings, the duration, and the conditions.
• No GIUSP classification on existing defects — if you find something wrong, classify it. Not classifying is itself a compliance failure.

Further Resources

For the full text of the regulations and standards referenced in this guide:

• GSIUR 1998 — Full Text (legislation.gov.uk)
• Gas Safe Register — Official Site
• IGEM Standards — Institution of Gas Engineers and Managers
• HSE Gas Safety Guidance

Published 2026-07-06. This article is for general guidance only and does not constitute legal or professional advice. Always refer to the relevant standards and consult qualified professionals for definitive requirements.