Instantaneous Gas Hot Water Installation Regulations: What You Need to Know

Feb 19, 2024

Installing an instantaneous gas hot water system (also known as a continuous flow system) or a gas water heater requires strict adherence to Australian plumbing and gas fitting regulations to ensure safety, efficiency, and compliance with local laws. Whether you’re upgrading from an older system or installing a new unit, understanding these regulations is crucial.

This guide covers key installation requirements, safety standards, and legal obligations to help you navigate the process smoothly.

Understanding Gas Hot Water Systems

Gas hot water systems are a popular choice for many homeowners due to their convenience, dependability, and energy efficiency. These systems use natural gas or LPG to power the burner that heats the water, providing a continuous supply of hot water. There are two main types of gas hot water systems: storage tank systems and instantaneous flow systems.

Storage tank systems store heated water in an insulated storage tank, ensuring that hot water is available whenever needed. These systems are ideal for households with high hot water demand, as they can store a large volume of heated water.

Instantaneous flow systems, on the other hand, heat water immediately as it is needed, without storing it. This type of system is highly efficient, as it only heats water on demand, reducing energy consumption and costs.

When choosing a gas hot water system, it’s essential to consider factors such as the size of the household, the number of bathrooms, and the desired level of energy efficiency. A larger household with multiple bathrooms may benefit from a storage tank system, while a smaller household might find an instantaneous flow system more suitable. It’s also important to ensure that the system is installed and maintained correctly to ensure safe and efficient operation.

Key Regulations for Instantaneous Gas Hot Water Installation

When installing an instantaneous gas hot water system, several regulations must be followed to ensure the safety of occupants and compliance with Australian Standards (AS/NZS 5601.1) for gas installations. It is crucial to maintain a minimum distance from flammable materials, such as ceilings and walls, and other devices to prevent fire hazards and ensure proper ventilation during operation. Below are the critical factors that licensed installers must consider.

✅ Gas Supply & Pressure Requirements

The gas supply line must be appropriately sized to meet the flow rate and heating capacity of the unit.
The system must have a dedicated gas line that can handle the required pressure to avoid fluctuating water temperatures.
All gas fittings and connections must comply with AS/NZS 5601.1 to prevent leaks and ensure safe operation.

✅ Venting & Flue Clearance

Instantaneous gas hot water systems produce combustion gases, requiring proper ventilation for the hot water unit.
The unit must not be installed indoors unless it is a room-sealed appliance with a properly vented flue system.
Outdoor installations must adhere to minimum clearance distances from:
Windows, doors, and vents (1.5m minimum).
Other gas appliances and air inlets.
Boundary walls and property lines (minimum 500mm clearance).

✅ Location & Installation Restrictions

Units must be installed in well-ventilated areas to prevent carbon monoxide buildup.
Direct sunlight, high-moisture areas, and enclosed spaces can impact system performance and longevity. Additionally, effective management of the cold water feed is crucial for optimal system performance and efficient heating.
The installation height should be easily accessible for servicing and maintenance.

✅ Water Supply & Pressure Limits

Mains water pressure must not exceed the manufacturer’s recommended limit.
A pressure-limiting valve may be required if local water pressure is too high.
Temperature control devices (tempering valves) must be installed to regulate safe hot water delivery (maximum 50°C for bathrooms as per AS/NZS 3500.4). All new and replacement hot water systems are required to have a tempering valve or temperature control device to ensure safety and compliance.

✅ Electrical & Compliance Requirements

If the unit requires electric ignition, it must be connected to a safe, compliant power source.
Hardwired models must be installed by a licensed electrician.
Installers must submit a Compliance Certificate upon completion, proving that the installation meets Queensland plumbing and gas fitting regulations and the standards set by the Technical Regulator.

Who Can Install an Instantaneous Gas Hot Water System?

In Australia, only a licensed plumber and gas fitter can legally install an instantaneous gas hot water system. DIY installations are not permitted and can result in:

Fines and penalties for non-compliance.
Voided warranties from manufacturers.
Serious safety hazards like gas leaks, fire risks, or carbon monoxide poisoning.

Before installation, always check that your installer is licensed, insured, and qualified for gas plumbing and continuous flow hot water systems.

Instantaneous Hot Water System Safety Features

Modern instantaneous gas hot water systems are designed with multiple safety mechanisms to comply with Australian Standards:

Flame failure detection – Automatically shuts off gas supply if the flame goes out.
Overheat protection – Prevents excessively high water temperatures.
Gas leak detection – Built-in sensors that shut off gas flow if a leak is detected.
Auto shut-off timer – Turns off the unit after extended operation to prevent excessive gas consumption.

These features, combined with professional installation and routine maintenance, ensure long-term safety and performance.

Do You Need Council Approval for Installation?

In Queensland, gas hot water system installations must comply with local council regulations. Some key requirements include:

New gas connections require approval from Energex or your gas provider.
Installers must register the installation with the Queensland Building and Construction Commission (QBCC).
If switching from electric to gas, a compliance check may be needed.

Always confirm local council rules before proceeding with installation.

Choosing the Right Instantaneous Gas Hot Water System

When selecting an instantaneous gas hot water system, consider the following:

Household size & hot water demand – Ensure the unit has a sufficient litres-per-minute (LPM) rating.
Gas type (natural gas vs LPG) – Choose a unit compatible with your existing gas supply.
Energy efficiency rating – Look for 5-6 star energy efficiency models to reduce running costs.
Installation location – Indoor models require flue ventilation, while outdoor units need weather protection.
Type of system – Consider whether a gas storage system or an instantaneous system is more suitable for your needs. Instantaneous systems provide hot water on demand without the need for a storage system, which can be more efficient and space-saving.

Need help choosing the right model? JR Gas & Water offers expert advice and installation across Brisbane & Gold Coast. Instantaneous systems do not store hot water, providing an unlimited supply and enhanced energy efficiency, making them ideal for various living situations, especially where space is limited.

Maintenance and Compliance

Regular maintenance is crucial to ensure the safe and efficient operation of gas hot water systems. Homeowners should check the system regularly for signs of wear and tear, such as leaks, corrosion, or faulty temperature and pressure relief valves. It’s also essential to follow the manufacturer’s guidelines for maintenance and repair to keep the system running smoothly.

In addition to regular maintenance, gas hot water systems must also comply with relevant regulations and standards. For example, the Australian Standard AS5601:2004 requires certification from a certifying body for compliance with the standard. Homeowners should ensure that their gas hot water system is installed and maintained by a licensed and experienced plumber who is familiar with the relevant regulations and standards.

By understanding how gas hot water systems work and following proper maintenance and compliance procedures, homeowners can enjoy a safe, efficient, and reliable supply of hot water. Regular checks and adherence to standards not only prolong the life of the system but also ensure the safety of the household.

Why Choose JR Gas & Water for Your Installation?

✔ Licensed Gas Fitters & Plumbers – Certified to install all major brands.
✔ Same-Day Service Available – Quick & hassle-free installations.
✔ Fully Compliant & Insured – All work meets Queensland gas safety regulations.
✔ Best Price Guarantee – Competitive rates with no hidden costs.
✔ 5-Star Customer Satisfaction – Trusted by homeowners across Brisbane & Gold Coast.