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Guide To Gas Installations In Caravans & RVs

Article by Peter Smith - Caravans Plus

This article has been put together to allow the DIY person to design their Caravan or Motorhome, taking into account the rules that need to be adhered to, to get a gas compliance certificate.

In some instances a gas fitter may permit the running of pipework during construction by a DIY builder, but as the person responsible for certification, the gas fitter will need to have full access to all pipework and all junctions to ensure it complies. It is recommended to have your gas fitter examine your plans, prior to construction to ensure any new standards are met.

This is NOT a guide to allow you to be a gas fitter, it allows you to design your caravan or motorhome to adhere to AS-5601


Exceptions are generally excluded from this brief guide. This means that you may be able to be exempt from some of the rules by complying in other ways. If you are unable to make your design work by following this brief guide, you may need to buy the full AS 5601.2 or seek the advice of the Licensed Gas fitter at the design stage.

There is also a companion guide for those replacing regulators or pigtails .


Who can do the gas installation?

A licensed plumber who is certified to carry out gas fitting is required for the installation, relocation or replacement of any gas appliance as well as the installation, relocation or modification of pipework. Renewal of regulators and pigtails is generally accepted to be maintenance.


Where can I place a gas cylinder?

A cylinder CANNOT be installed inside a Recreational Vehicle (RV). An RV includes Caravans, Motorhomes, Camper Trailers.

1) A gas cylinder can be installed in a compartment that is sealed from the inside of the RV, but vented to outside.A Red Reflective LP Gas Storage sticker is require to be fixed adjacent to the compartment.

Gas Cylinder in an external vented compartment

2) A gas cylinder can be mounted externally on a draw bar. It must be mounted vertically with the valve at the top. See below:

Gas cylinder mounted on a draw bar

The regulator is connected to the gas cylinder with a pigtail, min length 300mm. The regulator must be a two stage regulator mounted vertically to a rigid mount, with the vent pointing down. The pigtail should slope down from the regulator to the gas cylinder to prevent liquid gas reaching the regulator.


Regulators and Pigtails

There is a companion guide for those replacing regulators or pigtails that goes into more details about options.

Regulator to suit twin gas cylinders
All Pigtails sold by Caravans Plus, comply with AS 1869 Type C or exceed the standard.
Regulators must have a maximum outlet pressure of 3kPa. All regulators sold by Caravans Plus meet this requirement.

What size copper pipe should I use?

The size of the pipe depends on the distance the gas is required to travel and the appliances that will be connected, together with their gas consumption requirements. As this is a calculation that depends on the appliances you select, this should be verified with your gas fitter after your layout and appliances have been selected.

However as a rule of thumb and assuming the larger your RV is, then the bigger the appliances will be, most RV's up to 6 metres would use 5/16" copper pipe, and longer RV's may require 3/8" copper pipe.

There may also be a combination of sizes, where the main run may be 3/8" pipe and the branch lines to individual appliances may be 5/16".

1) Select the pigtail length and style.

2) Select the Regulator, Test Point and Change Over Valve.

3) Copper Pipe and copper saddles can be viewed here.


Where can pipe and junctions be placed?

Copper pipe must be located where it is not likely to suffer physical damage. If damage is likely, the pipe must be protected. A suitable method to prevent stone damage is to protect it within hose or pipe. The location must also ensure it cannot be damaged.

Where more than one appliance is to be installed, the main run of copper pipe shall be located outside the RV.
Each appliance shall have its own branch pipe.
Each branch pipe will enter the interior of the RV adjacent to the appliance.
Where a flexible hose is connected to an appliance, it shall not exceed 1200mm. More detail later.

Joins and junctions are not permitted within a sleeping area (or engine compartment).
Joins and junctions must be readily accessible for future maintenance.
There can be no joins between a main run and a shut-off valve on a branch to an appliance.

Pipe must be supported at least every 600mm in a horizontal run by non-ferrous metal clips. A maximum of 1250mm for vertical runs and a max of 150mm each side of a change in direction.

Pipe need to be supported

Protect when penetration walls or floor

Exposed Pipe needs to be protected


Where do I need to place valves? Can I use a gas hose?

Each appliance needs to have its own shut-off valve and it needs to be readily accessible.
Flexible hoses have a limited life span and are more easily damaged, so are discouraged. If essential they can be fitted only between a shut-off valve and an appliance. Max length inside an RV is 1200mm.
The standard appliance installation is fitted with copper pipe to provide maximum life span.

A gas valve is required for each appliance

Gas ball valve location
Gas Valves to isolate each appliance are listed below.

Gas Ball Valve, m-SAE-3/8 to m-SAE-3/8

Gas Ball Valve, m-SAE-3/8 to m-SAE-3/8

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$27.95
$16.25
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Gas Ball Valve, m-SAE-5/16 to m-SAE-5/16

Gas Ball Valve, m-SAE-5/16 to m-SAE-5/16

28 In Stock Now.
$18.45
View

Are there restrictions on which gas appliances can be used and where?

Gas appliances must be Low Pressure, ie operate at or below 2.75kPa, when fitted inside an RV. All gas appliances shown on the Caravans Plus website are Low Pressure unless stated as High Pressure.
A flueless Gas Water Heater CANNOT be used inside an RV.
Only Space (air) Heaters can be used where the combustion exhaust is sealed from the living area. Below is an example.

Truma Gas Heater - VarioHeat Eco - Cream CowlFree Shipping

Truma Gas Heater - VarioHeat Eco - Cream Cowl

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$2,475.00
$1,848.00
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Where the RV has a fuel tank, other than diesel, you must ensure there is a minimum distance of one metre between the fuel filler cap or fuel vent and the appliance flue or combustion air inlet.

Installation instructions must also be met if they exceed the minimums set out in AS 5601. In particular installation instructions for fridges and heaters that require outside flue ventilation should be studied to ensure minimum distances from inlet vents, windows and annex areas are adhered to. For example you will not be able to allow combustion exhaust to enter an annex.

Appliances must be secured to prevent movement.

Wall mounted gas lights are rarely used since the advances in LED lights, however if this affects you, you should consult the AS 5601.


What are the ventilation requirements?

Gas appliances can be grouped into two sections:
1) Those where the combustion and exhaust is already sealed from the living area. e.g. Space heaters, *Most Fridges, Hot Water Systems

* All current model Dometic and Thetford Fridges are Room Sealed.
In this section, the ventilation requirements for the appliances are already met if you follow the instructions of sealing the room, providing external ventilation and flue for each appliance.

2) Those that are not room sealed. e.g. Cooktops, Ovens, **Some Fridges

**Many older gas fridges fit this category

In the second section, there are additional requirements based on the combined gas consumption of all other appliances.
There is a requirement to have two openings that are permanent and unrestricted.
These vents need to be at opposite ends or sides, one high, one low. Camper Trailers only need to meet this when open. Pop-Tops need to meet this with roof up and have one open vent even when roof is down.

The lower vent is usually within the door, and should never be sealed. The upper vents can be wall mounted or combined within permanently vented roof hatches.

The formula is A = 3xT

A is the ventilation AREA in square centimetres, that must be met.
T is the TOTAL gas consumption of all appliances in the area measured in Megajoules per hour (Mj or Mj/h). If the appliance is rated in BTU instead of Mj, then divide BTU by 948 to get Mj

Examples of a couple of hatches that provide 50, 80 and 150 square centimetres of permanent ventilation each.

Fiamma Vent 28 F - White - 280x280mm - 07902-01-

Fiamma Vent 28 F - White - 280x280mm - 07902-01-

15 In Stock Now.
$149.50
$124.95
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Fiamma Vent 40 - White - 400x400mm - 04328B01

Fiamma Vent 40 - White - 400x400mm - 04328B01

5 In Stock Now.
$142.00
$119.95
View
Fiamma Roof Vent 50 - With Blind - 500x500mm - WHITE

Fiamma Roof Vent 50 - With Blind - 500x500mm - WHITE

11 In Stock Now.
$365.00
$219.95
View

3) There is also a Minimum Ventilation Area that depends on the size of your RV, no matter what appliances are fitted.
Up to 4 metres long - 240 cm2
4 to 5 metres long - 300 cm2
5 to 6 metres long - 360 cm2
Over 6 metres long - 420 cm2
These are to be split 50% between upper vents (within 300mm of highest ceiling point) and lower vents (within 150mm of floor). The CAMEC Odyssey Doors provide 238 cm2 permanent ventilation, so meet the lower vent requirements.


How much gas will I use?

Since you have now researched each appliance's gas consumption for the purpose of working out the ventilation requirements, you can also estimate how long your gas will last. Estimate the time used per day for each appliance, then total them up.
With appliances like stoves, remember you will rarely use all burners at once. With fridges, the operation time will vary depending on the outside temperature, how often you open the fridge and what the temperature on new items you add is. But make an educated guess. Water pump usage and HWS will depend on your maximum water storage.

An 8.5kg bottle (e.g. a swap size BBQ Bottle) will hold 17 litres of gas, that will provide approximately 420Mj of energy. So a Gas stove that uses 20Mj per hour, will burn for 21 hours on a full bottle of gas.


Reference: Guide to Gas Installations in Caravans & Motorhomes

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29 Comments

  • comment-avatar

    john

    distance from diesel appliance flue to centre of lag regulator

  • comment-avatar

    pip

    Hello I want to be able to attach and detach a portable gas hot water system, to a gas connection inside the kitchen cupboard in my van. Can you tell me what sort of regulator or adapters I need.. I know that the gas bottle has to be in a locked box only accessible from the outside, so besides the hose to the gas oven, a secondary hose would have to be run from the regulator I suppose, maybe with a shut-off tap too? Can you give me some ideas please?.. Thanks

  • comment-avatar

    Heinz

    Hi, I'm adding a 12V system to my caravan (battery, solar, fuses and switches) . Some switches and plugs will be very close to existing gas fittings (shut-off vale, stove, fridge) Are there any restrictions, regulations I need to take into account? ie minimum distances etc? Many thanks H

  • comment-avatar

    Mark Heaton

    Father inlaw is converting Ford transit van to basic camper was told he can fit gas bottle outside on rear door, I cant find info, only to fit on drawbar or in proper enclosure and ventilation if fitting in compartment. I would think fitting at back of car might be dangerous and affect insurance liability.

  • comment-avatar

    Faye Dowdy

    I would like to now what type of low pressure stove I can get for my camper

  • comment-avatar

    Leanne Martin

    You can't build in a gas water heat in a standard cupboard as you'll invalidate the insurance due to the fire that certainly come next. Added to that is nitrous oxide toxic gas entering the living compartment. Before you kill yourself and your family talk to a licensed gas-fitter.

  • comment-avatar

    Kai

    Can gas bottles be mounted open to air (underneath the body), of a school bus/motorhome conversion? I have seen this done and certified- but after reading this article it seems they need to be enclosed with a vent??

  • comment-avatar

    Peter

    They don’t need to be enclosed if there is a safe external position. The reference to enclosed is if they physically occupy space that is generally considered within the RV

  • comment-avatar

    Daniel

    can a chef upright l pg gas domestic cooker be installed in 16 ft caravan

  • comment-avatar

    Will

    Where can I buy the protective pipe for the copper pipe and the rubbers grommet

  • comment-avatar

    Peter

    There is no specific product to cover pipe. Black 12mm irrigation hose from Bunnings is ideal. Rubber grommets are available at many hardware stores and Clark Rubber.

  • comment-avatar

    GARY

    I have seen brand new RVs at the major motorhome business in Newcastle with the gas bottle inside the vehicle in a sealed lockable box accessible only by lifting the rear door of the vehicle. So this confuses me when apparently the rules state otherwise. When I questioned a gas fitting and repair shop about this...I was told there are different laws say in VIC... if that's where the RV was built...really confused now!!

  • comment-avatar

    Peter

    The reason for the rule is to prevent flammable gas entering the sleeping area. If the gas bottle is contained within a sealed compartment, and vented to the outside it would achieve the objective even if the sealed compartment is accessible from inside the RV.

  • comment-avatar

    Kevin

    This is typical of the gas industry. If the regulation states the venting to the outside from a SEALED compartment, then no access should be available from the inside! Otherwise you might as well put in a kitchen cupboard that is vented!

  • comment-avatar

    David

    Hi there Just to start i am going to be using a licenced plumber to do the work. im just in planing stage of building a camp trailer i have a large storage box on the front witch will have my kitchen ,fridge basically all storage but will never be occupied by a human , Now the kitchen pulls out 2m and i have a flexable cable tray so that all the water and 12volt can be connected all the time so that when i pull kitchen out i dont need to connect everything. By doin this i need a flexable gas pipe over 1200mm i just want to know if this is allowed as long as it is not in the human occupied area of the camper Cheers

  • comment-avatar

    Peter

    From your description it appears to meet the intention of the rules. Bare in mind a long constantly moving gas hose could be susceptible to damage. A ‘Gas Fuse’ would be a handy safety device in your situation where you probably will not see your hose every time you slide out your kitchen.

  • comment-avatar

    Steve

    I have a kink in the line that runs from the regulator to a brazed t piece can a joiner be fitted between that .Cheers

  • comment-avatar

    Peter

    A kink in a copper pipe is a definite safety issue and should be replaced. I expect ( but I am not licensed ) a braised connection would longer pass RV installation rules due to vibration fracture risk. I would replace the braised connection as well as the pigtail, unless it is an on-site RV.

  • comment-avatar

    Albe

    Hi I saw a YouTube on LPG servo refill port to an auto engine bottle. Can this be done to a normal camping type bottle or is it only for auto engine type bottle?

  • comment-avatar

    Peter

    Auto LPG should not be used for LPG appliances, THEY tell us.

  • comment-avatar

    Lance

    The reason you shouldn't use auto gas for gas bottles is simple. Gas appliances use PROPANE and automotive gas is often(almost always) a mix of propane and butane. It's quite rare to have pure propane for auto use and as such, it's a heavier gas. Some forms of butane(4 carbon atoms per molecule which can vary in structure from straight molecules to olefinic or isomers etc) can stay liquid just below 0 deg C so in very cold climates there is a risk of liquid reaching an appliance. Butane also burns differently so appliances won't function optimally. It's got nothing to do with what THEY tell us, it's a physically different gas. PS I am an oil refinery operator.

  • comment-avatar

    David

    Hi all I’ve been searching for an answer but can’t seem to find it so I thought I’d ask here. I want to mount my 2x 9kg gas bottle in my front toolbox but I’ve been told I can only do this if the vent on the 2 stage regulator is higher then the outlet on the gas bottle is this correct. I live in Qld.

  • comment-avatar

    Mick

    The change over valve & pigtails must be higher than the gas cylinder tap . A drain must be in the bottom of the tool box & LPGas storage sticker fitted . It's on the front of a caravan we assume ?

  • comment-avatar

    Tobias

    Hi, would a Muller vent with a 125mm cutout equate to 122 cm square permanent ventilation or is the opening of the venturi the crucial measure? Thanks

  • comment-avatar

    ST

    G'day, I am a licence gas fitter with a question but can't find any information What is the minimum distance I need between a outside hot water heater vent/flue and an opening window on a converted hi top van please?

  • comment-avatar

    Mick

    It would be the same as a house . Directly above 1000 mm , not directly below 500 mm horizontily from window

  • comment-avatar

    where in victoria can l obtain gas compliance certificate

  • comment-avatar

    where in victoria can l obtain gas compliance certificate

  • comment-avatar

    Ray

    Where externally can I store a spare gas bottle please?

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