All Practice Exams
100+ Free ACS MET1 Gas Meters Practice Questions
ACS MET1 Domestic Gas Meters Assessment practice questions are available now; exam metadata is being verified.
✓ No registration✓ No credit card✓ No hidden fees✓ Start practicing immediately
100+ Questions
100% Free
Loading practice questions...
Same family resources
Explore More UK Gas Safe / ACS Gas Assessments
Continue into nearby exams from the same family. Each card keeps practice questions, study guides, flashcards, videos, and articles in one place.
2026 Statistics
Key Facts: ACS MET1 Gas Meters Exam
100 Q
Practice Questions
OpenExamPrep
Up to 6 m³/h
Meter Capacity Scope
Gas Safe / ACS MET1 Standard
20 mbar
Tightness Test Pressure
IGEM/UP/1B
Within 600 mm
Equipotential Bonding Distance
BS 7671 / GSIUR
Every 5 years
ACS Re-assessment Cycle
ACS Scheme Rules
0800 111 999
National Gas Emergency Number
Gas Safe Register
ACS MET1 (Domestic Gas Meters) is the UK assessment required for Gas Safe registered operatives installing or exchanging primary and secondary domestic gas meters up to 6 m³/h capacity. The official assessment combines open-book written theory with a mandatory practical test on meter rigs. Key topics include Gas Safety Regulations (GSIUR 1998), BS 6400-1 meter box clearances, BS 7671 main protective equipotential bonding (10 mm² copper within 600 mm of meter outlet), IGEM/UP/1B tightness testing (20 mbar for 2 minutes, 4 mbar max drop for existing U6 installations with no smell of gas), ECV let-by testing (9-10 mbar), purge volume calculations, standing and working pressure checks, and GIUSP unsafe situation classifications (ID, AR, NCS). This practice bank offers 100 English-language study questions for the theory component.
Sample ACS MET1 Gas Meters Practice Questions
Try these sample questions to test your ACS MET1 Gas Meters exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1Under the Gas Safety (Installation and Use) Regulations 1998 (GSIUR) Regulation 3, what qualification must an engineer hold before installing, exchanging, or commissioning a domestic gas meter in the UK?
A.A valid Gas Safe Registration covering Core Domestic Natural Gas Safety (CCN1) and the MET1 domestic meter module
B.An unrestricted NVQ Level 2 in Plumbing and Domestic Heating without Gas Safe registration
C.A local authority building control registration card for electrical and gas services
D.A manufacturer product certificate for the specific electronic meter model being fitted
Explanation: GSIUR Regulation 3 requires anyone carrying out gas fitting work to be a member of a class of persons approved by the Health and Safety Executive (HSE), which in Great Britain is the Gas Safe Register. For domestic meters, the operative must hold CCN1 (or equivalent core) plus the MET1 assessment module. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
2What is the maximum badged gas flow capacity for a domestic meter covered under the scope of the ACS MET1 module?
A.Up to and including 6 m³/h (e.g. U6 / E6 meters)
B.Up to 16 m³/h (e.g. U16 commercial meters)
C.Up to 40 m³/h (e.g. U40 industrial diaphragm meters)
D.Unlimited capacity provided the inlet pressure is below 75 mbar
Explanation: The scope of ACS MET1 covers primary and secondary domestic gas meters with a measuring capacity up to and including 6 m³/h (typically U6, G4, or E6 meters). Meters above 6 m³/h fall outside MET1 and require non-domestic meter qualifications such as MET4 (diaphragm meters over 6 m³/h up to 40 m³/h) or CMET1. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
3What is the primary function of an Emergency Control Valve (ECV) installed on a domestic gas meter installation?
A.To allow the consumer or emergency operative to shut off the gas supply to the installation in an emergency or during maintenance
B.To automatically regulate the gas pressure down from medium pressure to 20 mbar working pressure
C.To measure the volume of gas consumed by downstream appliances for billing
D.To prevent back-siphonage of water into the gas service pipework
Explanation: An Emergency Control Valve (ECV) is fitted at the inlet of a primary gas meter installation to allow the gas supply to be isolated manually in the event of a gas leak, fire, emergency, or during installation work. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
4According to BS 7671 and GSIUR Regulation 18, where must the main protective equipotential bonding connection be made on a domestic gas installation?
A.On the consumer's hard metal pipework within 600 mm of the meter outlet connection, before any branch pipework
B.On the flexible corrugated meter connector on the inlet side of the governor
C.On the emergency control valve handle inside the external meter box
D.At the gas appliance burner manifold inside the boiler casing
Explanation: Main equipotential bonding must be connected on the consumer's hard metallic outlet pipework as close as practicable to the meter outlet (within 600 mm), before any branch, and on the load side of any meter control valve or insulating insert. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
5What minimum copper conductor cross-sectional area is required for main protective equipotential bonding under BS 7671 for a standard domestic gas installation?
A.10 mm²
B.4 mm²
C.2.5 mm²
D.16 mm²
Explanation: BS 7671 mandates a minimum copper conductor size of 10 mm² for main protective equipotential bonding connections to gas services in PME (TN-C-S) domestic installations. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
6What is the standard test pressure used when conducting a tightness test on a low-pressure natural gas domestic installation with a U6 meter per IGEM/UP/1B?
A.20 mbar
B.50 mbar
C.100 mbar
D.10 mbar
Explanation: Under IGEM/UP/1B, tightness testing for low-pressure natural gas installations (operating at 21 mbar nominal) is carried out at a test pressure of 20 mbar using a gauge or electronic manometer. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
7What is the required stabilization period before commencing the 2-minute timed tightness test under IGEM/UP/1B?
A.1 minute
B.5 minutes
C.10 minutes
D.30 seconds
Explanation: IGEM/UP/1B specifies a 1-minute stabilization period after raising the system pressure to 20 mbar to allow temperature and pressure conditions to settle before starting the official 2-minute test period. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
8During a tightness test on an existing domestic installation with appliances connected and a calculated Installation Volume (IV) of 0.008 m³, what is the maximum permissible pressure drop over the 2-minute test under IGEM/UP/1B Edition 4 (natural gas) if NO gas smell is detected?
A.4 mbar
B.0 mbar
C.8 mbar
D.1 mbar
Explanation: IGEM/UP/1B Edition 4 sets the permissible tightness-test drop by Installation Volume (IV), not by meter designation. For natural gas an IV in the band greater than 0.005 m³ and up to 0.010 m³ permits a maximum 4 mbar drop over the 2-minute test with appliances connected and no smell of gas. An IV of 0.008 m³ falls in this band, so 4 mbar is the limit. If there is any smell of gas the test fails. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
9What is the purpose of conducting a let-by test on the Emergency Control Valve (ECV) prior to performing a main tightness test?
A.To verify that the ECV shuts off gas completely and does not leak gas past the valve seat into the installation during testing
B.To check whether the meter index clock mechanism is recording gas flow accurately
C.To measure the maximum peak demand flow rate of the property
D.To test whether the main equipotential bonding cable carries stray electrical current
Explanation: A let-by test checks the integrity of the ECV valve seat. Pressure is set between 7 and 10 mbar for 1 minute with the ECV closed. If the pressure rises on the gauge, gas is leaking past the ECV, which would mask downstream installation leaks during tightness testing. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
10What is the nominal standing pressure expected at the test point of a low-pressure domestic natural gas meter when all appliances are turned off?
A.20 mbar (acceptable range 18.5 mbar to 21.5 mbar)
B.37 mbar
C.75 mbar
D.5 mbar
Explanation: Standing pressure for low-pressure natural gas is nominally 20 mbar, with an acceptable range of 18.5 mbar to 21.5 mbar at the meter outlet when no gas is flowing. Note: Local multiple-choice questions are an English-language study adaptation for ACS assessment.
About the ACS MET1 Gas Meters Practice Questions
Verified exam format metadata for ACS MET1 Domestic Gas Meters Assessment is pending. The practice questions above remain available while official exam length, timing, passing score, fee, and administrator details are reviewed.