LPG Basics

What is LPG?

Liquefied Petroleum Gas (LPG) is a cost effective fuel source used by many New Zealand homes and businesses for heating, cooking and vehicles. It is made up of a mixture of propane and butane gases. LPG is a naturally occurring by-product of natural gas extraction (60%) and crude oil refining (40%) – therefore we either use it or it is wasted.

How does LPG gas work?

LPG is stored in a cylinder, in a liquid state. In order to work it must undergo a phase change from liquid to vapour, known as vaporisation.When an appliance is turned on, the liquid is dispersed and changed to vapour by the outside temperature. The proportion of vaporised gas to liquid gas can differ dramatically in accordance with composition, and conditions of temperature and pressure.

What are the benefits of LPG gas?

There are a number of reasons to use LPG for your home or business. Some the main benefits include:

  1. A cleaner energy source – LPG produces less air pollutants then diesel, oil, wood or coal, and emits about 20% less CO2 than heating oil and 50% less than coal.

  2. A cost-effective energy source – With LPG gas bottles, you only pay for what you use, and not a drop more.

  3. A versatile energy source – LPG is extremely versatile and portable. It can be transported using sea, rail or road transport and is available in even the remotest of areas. LPG gas is the #1 choice for many New Zealanders for their heating and cooking, as it provides instant heat at the flick of a button and is made up of 90% propane, meaning it burns better in winter.

How do I get connected?

As long as you have a place to safely install gas cylinders, we can deliver 9kg or 45kg cylinders filled with Rockgas LPG to your home or business. This is your own personal gas supply and doesn’t require connecting to a gas network. A registered gasfitter will then connect your cylinders to your appliances and make sure everything is safe. As soon as one cylinder is empty, your automatic regulator will switch to the second. When this happens, just let us know and we’ll replace, the empty cylinder on the next delivery day in your area. That’s all there is too it.

How much LPG will I use?

Ongoing charges for bottled gas include a cylinder rental fee plus the cost of each cylinder refill. Check out the table to see how many cylinders you could expect to use each year. See our indication of how many bottles you might use each year:

Number of 45kg cylinders per year in an average household

No. people in household


Hot water

Heating, hot water & cooking













Please note that demand varies across the country and is dependent upon individual users.

How are the LPG cylinders set-up at my home?

You will have two or more cylinders connected to a pressure regulator. This is usually mounted on the wall between the cylinders. An automatic regulator is designed to switch from an empty cylinder to a full one without disrupting the supply. There is no need for you to do anything.

When do I order a refill? 





When the viewing window on your regulator, located between your two bottles, is green or clear, there is LPG in both bottles.



When the viewing window has turned completely red, it means one bottle is empty and it is time to order a new bottle.

What does the automatic regulator look like?

There are a few different types of automatic regulators, with slightly different systems for showing when a bottle is empty. If you have any queries, give us a call on 03 448 8808.

Handy hint… Don’t adjust the directional arrow pointing to an empty bottle – it shows us which one to replace when we come to do the changeover.

How do I test the level of LPG gas in my bottles?

You cannot test the level of LPG by shaking or tapping the bottle – you could damage the bottle in the process.

The level of LPG in the full bottle is just over three-quarters of the bottle’s height, allowing for the expansion of the LPG.

If you would like to check the level, use this safe and accurate method:

  1. Pour warm water down the side of the bottle
  2. Wait a few moments
  3. Run your hand down the side of the bottle
  4. It will feel cool to the touch at the level of the LPG

How do I exchange my empty gas bottle?

If your gas is running low and you need a replacement bottle, just give us a call on 03 448 8808 or order gas online, and we will deliver a new bottle on the next delivery day.

Bottle exchange is done by one person, and we take the health and safety of our staff very seriously, so if you are having LPG bottles delivered, there are a few safety non-negotiables you will need to consider.

Obstacles - Are there any other obstacles that would make it difficult to deliver and install a large gas bottle? (Think 1.3m high.) Trolley access over delicate or decorative surfaces should be avoided, so ideally there’s a firm path for our delivery person.

Stair access - If access by stairs cannot be avoided, stair risers need to be less than 200mm high, treads more than 200mm wide, and the total rise of the steps needs to be no more than 1.5m.

House proximity - A full bottle weighs 90kg! Can our delivery person get close enough to the side of the house to unload the bottle without putting themselves at risk of injury?

Steep driveway - Can your driveway handle heavy vehicles? Is it too steep, soft, narrow or slippery/lacking grip?

Long driveway - Do you have a particularly long driveway? Is there room for a large vehicle to turn around?

If we cannot safely access your property for any reason, we will contact you and try to resolve the problem. We will also leave a card behind detailing the problem.

A few other simple things will make all the difference for our delivery person or meter reader:

  • Keeping your dog on a lead
  • Making sure vegetation is trimmed back
  • and safe
  • Making sure steps and pathways are safe
  • and secure

If have any concerns, call us on 03 448 8808.