Bottled Gas: Where the Shut-Off Is, and What to Check Before You Need It

People who have lived overseas often ask us the same thing: why is there no gas tap on the wall inside the kitchen? In a number of countries there is a valve mounted high on the wall in plain sight, and you reach up and turn it.

If you are on bottled LPG in New Zealand, the answer is simple. The shut-off is on the bottles, outside. Nothing is hidden. It is just somewhere else.

This post is about bottled LPG specifically. Reticulated natural gas works differently and the meter arrangement varies, so we have kept this to the system most Auckland houses on gas actually have.

Where it is

Outside, at the cylinders.

Each cylinder has its own valve on top. Between them there is usually an automatic changeover regulator, which switches supply from an empty bottle to the full one so you do not run out mid-shower. To shut the gas off to the whole property, you close the valves on the cylinders.

You do not need a plumber, a tool or a key to do that. It is the reason the valve is where it is.

The valve convention worth knowing

Manual shut-off valves in the gas pipework itself are quarter-turn, and they are built so you can read them at a glance: handle in line with the pipe means open, handle across the pipe means closed. The standard requires the handle to be made so it cannot be fitted the wrong way round, which is why you can trust what you are looking at.

It is the same convention as a lever valve in a water meter box, so once you know one you know the other. Cylinder valves themselves are usually a handwheel you wind closed rather than a lever.

Your appliances have their own isolation too

This is what answers “but where do I turn off just the cooker”.

A freestanding cooker on a bayonet unplugs at the bayonet point. That is a self-sealing quick-connect, and it is the isolation for that appliance. It is also why you can pull the cooker out to clean behind it.

Other appliances connected by a hose must have either a manual shut-off valve and union at the inlet end of the hose, or a quick-connect device that shuts the gas off automatically when disconnected. So there is a valve, it is just at the appliance rather than on a wall in the middle of the room.

A califont or a gas fireplace will normally have an isolation valve at the unit.

If you cannot find any isolation for an appliance, that is worth checking rather than assuming. An appliance with no accessible means of isolation is a problem in itself.

Bottles indoors: allowed, but with conditions

Most installations put the cylinders outside, and the standard’s own note says plainly that cylinders should be located outside the building. Where a cylinder is indoors feeding a cooktop, clause 6.10.1.8 sets conditions, and they are worth knowing because they are commonly breached in older work:

The cylinder must be no more than 9 kg (25 L water capacity).
It must not be in the same compartment as a power point or an electrical appliance, so not sharing a cupboard with a dishwasher or a waste disposal.
The compartment must be ventilated directly outside, with a vent of at least 1000 mm² at low level.
The hose assembly must be no longer than 1 m.
No jubilee clips.
Copper piping wherever the line passes through a wall or a cupboard.

If you have a bottle under a bench in a cupboard with a power point and a long flexible hose, that is not a borderline call. It is worth having looked at.

Why the vent is at the bottom

Because of the one physical fact that changes everything about a bottled gas leak.

LPG is heavier than air. It sinks. A leak does not disperse upwards the way natural gas does; it flows downhill and pools in low places, in pits, drains, under a floor, on a garage floor, in the bottom of a cupboard. That is exactly why a cylinder compartment has to be vented at low level to outside, and why a whiff of gas near ground level outdoors is worth taking seriously rather than assuming it will blow away.

It also means the sensible place to sniff is low, not at head height.

If you smell gas

Find the cylinder valves before you need them, not during.

If you do smell gas: do not operate any electrical switch, including the light on the way out. Close the cylinder valves if you can reach them safely. Open windows and doors, get everyone outside, and ring the gas emergency number for your supplier from outside the house. It is on your bill and usually on the bottles.

Then let a gasfitter turn it back on. Relighting appliances after a fault, particularly anything with a standing pilot, is where we come in. More on what we actually do on a gas smell callout in gas work at home.

Worth doing this weekend

Walk outside to the bottles. Look at the valves and work out which way closes them. Check the changeover regulator is not dripping, weeping or corroded, because that is the part we most often find leaking. Show whoever else lives in the house.

Then check inside: can you see isolation at the califont? Is there a bayonet behind the freestanding cooker? Two minutes now is worth a lot at the moment you actually need it.

Not sure what you are looking at? Send us a photo of the bottles and the regulator.

Common questions

Can I turn the gas off myself?

Yes. Closing a cylinder valve is not gasfitting work, it is the safety measure the valve exists for, and you should not hesitate if you think something is wrong. What you should not do is take anything apart, disconnect an appliance from a fixed line, or turn it back on and hope. Turning gas back on after a fault, and relighting appliances safely, is a gasfitter’s job.

My bottles are behind a locked gate. Is that a problem?

The requirement through the standard is that isolation is accessible, so a valve nobody can reach in an emergency is worth raising. In a rental, tell the property manager. If access is genuinely restricted, that is an issue with how the installation was arranged rather than something to live with, and it is usually straightforward to sort.

I live in a unit or apartment. Where is mine?

Where a building has multiple occupancies, each one has to have its own quarter-turn shut-off valve, accessible and where practicable outside that occupancy, with a durable permanent sign identifying it as a gas valve. Where several buildings run off one supply, each building needs a valve at its point of entry, accessible and external, signed GAS VALVE. Ask the body corporate or building manager to show you yours and take a photo, because working it out at midnight is the wrong time.

The bottles are emptying faster than they used to. Is that a leak?

It might be, and it might be the bottle side rather than your pipework. We attended a property where a hissing sound and a smell were reported and a 45 kg bottle had emptied unusually fast. We carried out a bubble leak detection test and a pressure test, demonstrated both on site, and the installation tested sound with no leak. Since a bottle-side fault cannot be ruled out once the bottle is empty, the next step was the supplier. Test the installation first, then talk to whoever delivers.

Do I need to turn the gas off when I go away?

For a long trip it is a reasonable precaution and there is nothing to it beyond closing the valves. One thing to plan for: anything with a standing pilot, such as an older storage water heater, will go out and need relighting when you get back, so do not expect hot water on the first night home.