Acceptable and unsuitable gas meter positions: access to the ECV, ventilation, separation from electrics, heat and damage, and escape routes.
A meter position has to do three things: keep the meter and emergency control valve (ECV) reachable, let any small escape disperse safely, and protect the meter and its joints. Most location questions come back to one of these.
1. Keep it reachable
The ECV sits upstream of the meter, so closing it shuts off every appliance at once. It must be readily accessible wherever the meter is, so the supply can be isolated quickly in an emergency. Ready access also lets the meter be read, inspected and maintained.
- Keep the area clear: stored items in front of the ECV must be removed so it can be reached and operated quickly.
- The ECV must turn by hand. If it is painted over or seized so that it needs tools, do not force it: report it so an authorised person repairs or replaces it.
- The emergency notice at the ECV tells anyone who smells gas to turn the supply off there and gives the gas emergency number.
2. Let an escape disperse, away from ignition
- Never in an unventilated cupboard or void: a leak could collect and risk explosion or asphyxiation.
- Never in a sealed cupboard alongside electrical equipment: an escape could build up next to something that could ignite it. This is the least suitable position of all.
- Keep separation from consumer units, other electrical equipment and ignition sources, so an escape is less likely to be ignited and both services can be worked on safely.
- In a cellar or basement, natural gas tends to rise and collect at high level, so high-level ventilation and gas detection need particular attention. It also mixes with air, so lower levels are not automatically safe.
- Not where escaped gas could enter the building or where the meter would adversely affect the means of escape. A new meter in a building with two or more floors above the ground floor is not sited in a sole escape route; elsewhere such a position needs fire protection, such as a fire-resistant meter or housing or a thermal cut-off, if it cannot reasonably be avoided.
3. Protect the meter and pipework
- Keep it away from excessive heat and likely damage from knocks, vehicles or weather.
- In an integral garage, protect the meter and pipework from vehicle impact and keep them clear of ignition sources.
- Never use meter pipework to support a shelf or other load: strain or impact on the joints can open a leak.
Common positions
Each still has to meet the requirements for that position:
- an external meter box on an outside wall
- a semi-concealed box
- an integral garage position protected from vehicles
- an internal or communal position, provided the ECV stays readily accessible and the housing is ventilated
Exam cues
- Least suitable position: a sealed, unventilated cupboard next to electrics.
- Why keep a meter accessible? So the supply can be isolated quickly in an emergency.
- Cellar meter: natural gas rises, so think high-level ventilation.