Vulcan Duomax 400L Electric Storage Hot Water System

Buy the Vulcan Duomax 400L Electric Storage Hot Water System online from Hot Water Outlet, with fast delivery available across Australia and same day delivery available in select metro areas on eligible orders.

The Vulcan Duomax 400L is a large electric storage hot water system designed for larger families, rental properties and homes with higher daily hot water demand. With 400L hot water delivery, a 3.6 kW single element, vitreous enamel lined cylinder and indoor or outdoor suitability where compliant, it is a practical supply-only replacement option for customers upgrading or replacing a large electric hot water system.

Hot Water Outlet supplies hot water systems, valves, pipework, fittings, connections, spare parts and accessories across Australia, making it easier to order the unit and related hot water parts in one place.

About the Vulcan Duomax 400L Electric Water Heater

The Vulcan Duomax 400L is an electric storage hot water system that heats and stores water inside a vitreous enamel lined cylinder.

It is designed for households that need more stored hot water capacity than common 250L or 315L electric hot water systems. The 400L size may suit larger homes, multiple occupants, families with higher shower demand, properties with baths, rental homes or customers replacing an existing 400L electric storage unit.

This 3.6 kW single element model is commonly selected where a large electric storage unit is required and the property has suitable plumbing, electrical supply, access, water pressure and space.

Buy Vulcan Duomax 400L Supply Only

Hot Water Outlet sells the Vulcan Duomax 400L Electric Storage Hot Water System as a supply-only product for customers across Australia.

The product price is for the hot water system only. Installation, old system removal, disposal, valve kits, electrical work, plumbing alterations, pipework changes, pressure control, base or tray requirements and compliance upgrades are not included unless clearly stated on the product page or selected separately.

Supply only is best for customers who already have a licensed plumber and electrician arranged, or who want to order the unit online and organise installation separately.

Before ordering, confirm the model, size, electrical requirements, water pressure, connection layout, delivery access and installation requirements with your licensed installer.

Fast Delivery Across Australia

Hot Water Outlet supplies electric hot water systems, valves, fittings, pipework, spares and accessories across Australia.

Fast delivery is available on eligible stocked products, with same day delivery available in select metro areas depending on stock, order time, product size and delivery location.

The Vulcan Duomax 400L is a large and heavy electric storage system, so delivery access should be checked before ordering. Consider driveway access, stairs, steep blocks, narrow side paths, unit complexes, raised platforms, tight laundries, loading zones and whether someone will be available to receive the delivery.

Is the Vulcan Duomax 400L Right for Your Home?

The Vulcan Duomax 400L may suit customers who need a large electric storage hot water system with high stored water capacity.

It may be suitable if:

You want a 400L electric storage hot water system
You are replacing an existing large electric water heater
Your household has high daily hot water use
You want more stored capacity than a 315L electric system
You want a single element electric water heater
You want a vitreous enamel lined cylinder
You need a system suitable for indoor or outdoor installation where compliant
You have suitable access, water pressure, drainage and installation space
You have a suitable electrical connection or can arrange electrical work
You already have a licensed plumber and electrician arranged

It may not be suitable without extra checks if:

The system is being moved to a new location
Existing valves are old, missing or unsuitable
Electrical upgrades are required
The existing circuit does not suit a 3.6 kW element
Drainage or safe tray requirements apply
Water pressure control is required
Pipework changes are needed
Access is restricted
The old system needs removal or disposal
The location does not suit the tank size, weight or service access
A smaller system may better suit the household’s usage pattern

Key Features

400L electric storage hot water system
Vulcan Duomax range
Manufacturer part number: 6D1400G7
Vulcan product reference: 661400G7
Tradelink product code: 309856
3.6 kW single element
Lead free model listing
400L hot water delivery
Suitable for larger families with high hot water demand
Maximum listed people serviced: 9, based on stated usage conditions
Vitreous enamel lined cylinder
Suitable for internal and external installation where compliant
Suitable for connection to off-peak tariff
Rp 3/4 hot water connections
850 kPa ECV setting
680 kPa maximum water supply pressure with ECV
800 kPa maximum water supply pressure without ECV
1000 kPa relief valve pressure
111 kg empty weight listed by Vulcan
118 kg shipped weight listed by Vulcan
1840 mm high x 690 mm wide x 730 mm deep
WaterMark approved
10 year cylinder warranty and 12 months parts and labour listed in product specification, subject to current warranty terms

Quick Specs

Brand: Vulcan
Range: Duomax
Product: Vulcan Duomax 400L Electric Water Heater
Product Code: 661400G7
Manufacturer Part Number: 6D1400G7
Tradelink Product Code: 309856
System Type: Electric storage hot water
Fuel Type: Electric
Tank Volume / Hot Water Delivery: 400L
Recommended Household Size: Larger family homes, up to 9 people based on stated usage conditions
Installation Type: Internal or external where suitable
Element Type: Single element
Element Rating: 3.6 kW
Tariff Suitability: Suitable for connection to off-peak tariff
Cylinder Type: Vitreous enamel lined cylinder
Water Connections: Rp 3/4
ECV Setting: 850 kPa
Maximum Water Supply Pressure with ECV: 680 kPa
Maximum Water Supply Pressure without ECV: 800 kPa
Relief Valve Pressure: 1000 kPa
Dimensions: 1840 mm high x 690 mm wide x 730 mm deep
Tank Diameter / Width: 690 mm
Weight Empty: 111 kg listed by Vulcan
Weight Shipped: 118 kg listed by Vulcan
Trade Listing Weight: 112 kg weight and 120 kg approximate empty weight listed by Tradelink
Lead Free: Yes, based on trade listing
WaterMark: Yes
Warranty: 10 year cylinder warranty and 12 months parts and labour listed in product specification, subject to current warranty terms

Vitreous Enamel Lined Cylinder

The Vulcan Duomax 400L uses a vitreous enamel lined cylinder.

This lining helps protect the inside of the cylinder and supports long-term electric storage hot water performance when the system is installed and maintained correctly.

Water quality, pressure control, correct valve selection, anode maintenance and compliant installation all play an important role in the service life of any electric storage water heater.

Large 400L Storage Capacity

The 400L capacity makes this Vulcan Duomax model suitable for homes with higher daily hot water demand.

It may suit larger families, rental properties, bigger homes, properties with multiple occupants or households replacing an existing 400L electric storage unit.

The right size still depends on shower length, shower flow rates, baths, laundry use, climate, tariff setup and household routines. If your old hot water system often ran out of hot water, do not assume the same size is always the right replacement without checking usage and recovery needs.

Single 3.6 kW Element

This Vulcan Duomax 400L model is the 3.6 kW single element version.

A 3.6 kW element may suit many replacement installations where the existing electrical setup is compatible. Electrical suitability should still be checked before ordering or installation.

Electrical work, circuit changes, isolator upgrades and compliance upgrades are not included in the supply-only product price.

Off-Peak Tariff Suitability

The Vulcan 400L electric water heater is listed as suitable for connection to off-peak tariff.

This can suit large electric storage systems where the tank heats during off-peak electricity periods and stores hot water for later use. Tariff setup, recovery time and household usage should be checked before choosing the system.

A 400L off-peak electric storage system may be useful where the home needs a large volume of stored hot water ready across the day.

Indoor or Outdoor Installation Suitability

The Vulcan Duomax 400L is suitable for internal or external installation where the location meets the required plumbing, drainage, access, electrical and compliance requirements.

For indoor locations, safe tray, drainage, service access and leak protection requirements should be checked before installation.

For outdoor locations, the system location must be suitable for weather exposure, base support, plumbing connections, electrical compliance and future service access.

Connection Layout

The supplied source text notes that the Vulcan product page refers to left handed connections, while the trade listing identifies system connections as dual handed.

Because product variants and supplier listings can differ, the supplied model’s connection layout should be checked before installation. This is especially important for like-for-like replacement work where pipework alignment affects installation time, parts and cost.

Water Pressure Requirements

The Vulcan Duomax 400L has an ECV setting of 850 kPa, maximum water supply pressure of 680 kPa with ECV, maximum water supply pressure of 800 kPa without ECV and relief valve pressure of 1000 kPa.

If incoming water pressure is too high, pressure control may be required. Valve requirements should be checked before installation, especially when replacing older systems where existing valves may be worn, missing or non-compliant.

Lead Free Model Listing

The trade listing identifies this model as a lead free Duomax 400L electric water heater.

Lead free product listings are becoming increasingly important in plumbing product selection. Final suitability should still be confirmed against the product supplied, local requirements and the installer’s compliance checks.

Large System Delivery and Handling Considerations

The Vulcan Duomax 400L is a large, heavy electric storage hot water system.

Vulcan lists the empty weight as 111 kg and shipped weight as 118 kg. The trade listing shows 112 kg weight and 120 kg approximate empty weight.

Before ordering, check whether the delivery location can safely accept a large hot water system. Stairs, steep blocks, narrow access, tight cupboards, apartment buildings, raised platforms and difficult delivery paths can affect delivery and installation planning.

Vulcan Duomax 400L vs 315L Electric Storage

The Vulcan Duomax 400L offers more stored hot water capacity than a 315L electric storage unit.

A 315L electric system may suit many medium to large households, while the 400L model may be better for larger homes, higher shower use, multiple occupants, homes with baths or properties that regularly run out of hot water with a smaller tank.

The right size depends on usage patterns, tariff setup, recovery needs and whether the household genuinely needs the extra stored capacity.

Vulcan Duomax 400L vs Heat Pump Hot Water

The Vulcan Duomax 400L electric storage system uses an electric element to heat stored water.

A heat pump hot water system uses heat from the surrounding air to heat stored water more efficiently under suitable conditions.

The Vulcan Duomax 400L may suit customers wanting a straightforward large electric storage replacement. A heat pump may suit customers looking for an energy-efficient upgrade where the location has suitable airflow, drainage, electrical supply, space and noise considerations.

The better option depends on the property, budget, available space, household hot water use, tariff setup and installer advice.

Vulcan Duomax 400L vs Instant Electric Hot Water

The Vulcan Duomax 400L stores a large volume of hot water, while an instant electric system heats water as it flows through the unit.

A 400L storage system is generally better suited to whole-home, high-demand hot water use than most instant electric systems. Instant electric units may suit point-of-use applications, but they often require specific electrical capacity and may not suit larger family homes.

Common Uses

Large electric hot water system replacement
400L electric storage replacement
Larger family homes
Homes with high hot water usage
Properties with multiple occupants
Rental properties
Investment properties
Renovation projects
Properties replacing an existing 400L electric unit
Homes suited to off-peak electric hot water
Indoor installations with compliant drainage and access
Outdoor installations with suitable base and weather exposure
Supply-only orders where a licensed installer is already arranged

Suitability depends on household size, hot water usage, tariff setup, installation location, plumbing condition, electrical supply, water pressure, access, drainage and compliance requirements.

Valves, Fittings and Parts to Check Before Ordering

A large electric storage hot water system may require more than the main tank. Depending on your existing setup and installer requirements, compatible valves, pipework, fittings or accessories may also be needed.

Check whether your installer requires:

Tempering valve
PTR valve
Expansion control valve
Pressure limiting valve
Isolation valve
Non-return valve
Duo valve
Hot water connection kit
Copper or braided connections where suitable
Pipework fittings
Drainage parts
Safe tray for indoor installation
Base or support requirements
Electrical connection parts
Anode option suitable for local water conditions

Hot Water Outlet also sells hot water valves, connections, spare parts and accessories, making it easier to order the system and related products in one place.

Why Buy From Hot Water Outlet?

Hot Water Outlet is focused on hot water supply across Australia. We sell hot water systems, valves, pipework, fittings, connections, spare parts and accessories online, with fast delivery options available on eligible products.

Buy from Hot Water Outlet for:

Supply-only hot water systems
Fast delivery across Australia
Same day delivery in select metro areas on eligible orders
Electric, gas, heat pump and instant hot water products
Hot water valves, pipework and fittings
Spare parts and accessories
Clear product information
Online ordering for homeowners, trades, landlords and property managers
Hot water products from trusted brands like Vulcan

Hot Water Outlet does not install hot water systems directly. If you need help with installation, we may be able to help organise a quote from a reputable installer where available, or you can arrange your own licensed plumber and electrician.

Frequently Asked Questions

Can I buy the Vulcan Duomax 400L supply only?

Yes. Hot Water Outlet sells the Vulcan Duomax 400L as a supply-only electric hot water system. The product price is for the unit only and does not include installation, valve kits, old system removal, disposal, electrical work, pipework changes or compliance upgrades unless clearly stated.

What size is the Vulcan Duomax 400L?

The Vulcan Duomax 400L has 400L hot water delivery.

How many people is the Vulcan Duomax 400L suitable for?

Vulcan lists the 400L model as suitable for a maximum of 9 people based on stated usage conditions. Real suitability depends on shower length, outlet flow rates, water temperature, climate, tariff setup and household usage patterns.

What is the element size?

This model has a 3.6 kW single element.

Is it single element or twin element?

This model is listed as a single element electric water heater.

Can it be installed indoors?

Yes, it can be installed indoors where the location meets access, drainage, plumbing, electrical and compliance requirements. Indoor installations may require safe tray and drainage provisions.

Can it be installed outdoors?

Yes, it can be installed outdoors where the location is suitable and compliant. The base, weather exposure, service access, pipework and electrical requirements should be checked before installation.

Is it suitable for off-peak tariff?

Yes. Vulcan lists the 400L model as suitable for connection to off-peak tariff.

What are the dimensions?

The listed dimensions are 1840 mm high x 690 mm wide x 730 mm deep.

What does it weigh?

Vulcan lists the empty weight as 111 kg and shipped weight as 118 kg. The trade listing shows 112 kg weight and 120 kg approximate empty weight.

What are the water connections?

The listed water connections are Rp 3/4.

What is the ECV setting?

The listed ECV setting is 850 kPa.

What is the maximum water supply pressure?

The listed maximum water supply pressure is 680 kPa with ECV and 800 kPa without ECV.

What is the relief valve pressure?

The listed relief valve pressure is 1000 kPa.

Is it lead free?

The trade listing identifies this model as lead free.

What is the manufacturer part number?

The manufacturer part number is 6D1400G7.

What is the Vulcan product code?

For the 3.6 kW model, use Vulcan product reference 661400G7.

What is the Tradelink product code?

The Tradelink product code is 309856.

Does it have dual handed connections?

The supplied source text notes that the trade listing identifies the system connections as dual handed, while the Vulcan product page refers to left handed connections. The supplied model should be checked before installation.

Is it suitable for replacing an old large electric water heater?

Yes, it may suit like-for-like replacement of an older large electric storage water heater, provided the location, dimensions, connections, electrical supply, water pressure and compliance requirements are suitable.

Do I need new valves?

New valves may be required depending on the existing installation, valve age, pressure requirements and compliance needs. Ask your licensed installer to confirm whether you need a tempering valve, PTR valve, expansion control valve, pressure limiting valve or other hot water fittings.

Do I need a plumber and electrician?

Yes. A licensed plumber is required for hot water plumbing work, and a licensed electrician may be required to confirm or complete electrical work for the system.

Does Hot Water Outlet install this system?

Hot Water Outlet sells supply-only hot water systems and parts. We do not install hot water systems directly. If needed, we may be able to help organise a quote from a reputable installer where available.

Is same day delivery available?

Same day delivery may be available in select metro areas on eligible orders. Availability depends on stock, order time, product size and delivery location.

Do you deliver Australia wide?

Yes. Hot Water Outlet supplies hot water systems, valves, fittings, spares and accessories across Australia, with delivery options depending on stock, product size and location.

What warranty applies to the Vulcan Duomax 400L?

The product specification shows a 10 year cylinder warranty and 12 months parts and labour, subject to current warranty terms. Warranty details should be checked before purchase because terms can depend on model, installation and manufacturer conditions.

Order the Vulcan Duomax 400L Online

Order the Vulcan Duomax 400L Electric Storage Hot Water System online from Hot Water Outlet. With 400L hot water delivery, a 3.6 kW single element, vitreous enamel lined cylinder and fast delivery options across Australia, it is a practical supply-only choice for customers replacing a large electric storage hot water system.

Tempering Valve and Element Information

*Element size information:
All electric hot water units are supplied as standard with a 3.6kW element unless otherwise stated on the product page, invoice, or order confirmation.

If a different element configuration is requested, such as 1.8kW or 2.4kW, the hot water unit may still arrive with the standard 3.6kW element fitted from the manufacturer. The requested 1.8kW or 2.4kW element will be supplied separately with the order for installation by a suitably licensed electrical contractor or licensed electrical licence holder.

Any element changeover, electrical connection, disconnection, wiring, testing, or modification must be carried out by a licensed electrical contractor or licensed electrical licence holder. Elements must not be changed, connected, modified, or tested by an unlicensed person.

Alternative elements supplied for non-standard configurations may be generic replacement elements and may not be the same brand as the hot water unit unless specifically stated. Generic elements are supplied to suit the requested element size and electrical configuration, but final suitability must be checked by the licensed installer before installation.

1.8kW and 2.4kW elements supplied separately with a hot water unit include a 12-month supply-only parts warranty from the date of purchase, provided the element has been correctly installed by a licensed electrical contractor or licensed electrical licence holder and used under normal operating conditions.

This element warranty covers the replacement supply of the element only. It does not include labour, call-out fees, electrical work, plumbing work, fault finding, removal, reinstallation, testing, travel, downtime, damage caused by incorrect installation, or any other associated costs. Warranty may be declined where the element has been incorrectly installed, dry-fired, modified, damaged, connected to incorrect voltage or wiring, affected by power issues, used in unsuitable water conditions, or installed by an unlicensed person.

Proof of purchase, installer details, electrical licence details, photos, and/or return of the faulty element may be required before a warranty claim is approved.

**Tempering valve information:
Where a hot water system is capable of delivering water above 50°C, a compliant tempering valve must be installed to control the temperature delivered to personal hygiene fixtures such as showers, baths, basins, and bathroom outlets. This helps reduce the risk of scalding and assists with meeting plumbing compliance requirements.

A tempering valve blends hot and cold water to deliver a safer controlled outlet temperature to required fixtures. The hot water unit itself may store water at a higher temperature, but the water delivered to personal hygiene outlets must be controlled where required by plumbing regulations.

If your property already has a suitable, compliant tempering valve installed, your licensed plumber can assess whether it is appropriate for use with the new hot water system. Existing valves may not always be suitable due to age, condition, compliance requirements, valve type, location, or system compatibility.

If a compliant tempering valve is not already installed, or if the existing valve is unsuitable, one must be supplied and installed by a licensed plumber as part of the hot water installation.

Tempering valves are not automatically included with every supply-only hot water unit unless specifically selected, listed as included, or purchased as part of a suitable valve kit. If a tempering valve is required, please purchase the appropriate valve kit with your order or arrange for your licensed installer to supply and install the correct tempering valve on site.

It is the customer’s responsibility to ensure the installation is completed by appropriately licensed trades and that all required valves, fittings, electrical work, plumbing work, and compliance requirements are allowed for as part of the installation.

Buying a new hot water system or hot water part should be simple. Hot Water Outlet helps you compare hot water systems, valves, thermostats, elements, pipework and fittings in one place, so you can choose the products that suit your home, budget and hot water needs without the back and forth.

Whether you already know exactly what you need or you are still comparing electric, gas, instant gas, gas storage or heat pump hot water options, Hot Water Outlet makes it easier to order with confidence.

Why Customers Choose Hot Water Outlet

Hot Water Systems and Parts in One Place

Shop hot water systems, valves, thermostats, elements, pipework and fittings online from one focused hot water store. Choose the system first, then add the parts and accessories needed for your setup.

Clear Product Pricing Before Checkout

See your hot water system price upfront, then add common valves, fittings or accessories before placing your order. This makes it easier to plan your purchase and compare options before checkout.

Product Details That Actually Help

Key specs, sizing details, tank capacity, flow rate, gas type, energy source, dimensions, warranty information, product features and suitability notes are shown clearly, so you can compare hot water systems properly before you buy.

Valves and Accessories Available

Where relevant, you can add common hot water parts such as tempering valves, pressure relief valves, duo valves, non-return valves, thermostats, elements, pipework and fittings to help complete your order.

Built for Australian Hot Water Buyers

Hot Water Outlet is focused on hot water systems and accessories for Australian homes, rentals, renovations and replacement projects. Browse trusted brands and compare practical options for common household hot water needs.

One Simple Online Order

Add your hot water unit and selected parts to cart in one order, instead of searching across multiple suppliers for systems, valves, fittings and accessories.

Practical Help Before You Buy

Not sure which hot water system, size, energy type or accessory is right? Hot Water Outlet gives you a clearer way to compare electric hot water systems, heat pump hot water systems, gas storage hot water systems and instant gas hot water units before you order.

Designed To Make Your Decision Easier

Hot Water Outlet is built for customers who want a faster, clearer and more convenient way to buy hot water systems and hot water parts online.

Instead of guessing which product suits your home, searching multiple suppliers, or trying to match accessories separately, you can review the system, compare the specifications and add common hot water parts before checkout.

Choose your hot water system.

Add the valves and accessories you need.

Compare product details before checkout.

Order online with confidence.

It is a simpler way to buy the hot water products and parts that matter most.

Important Note

Product suitability can vary by property, existing services, energy source, gas type, available space, connection points, pressure requirements and local compliance requirements. Always check product specifications carefully and confirm the selected hot water system, valves, fittings and accessories are suitable for your property before ordering.

Standard Delivery: 2–8 business days

Express Delivery: 1–4 business days

90% of products are delivered the next business day where stock, postcode eligibility and freight availability allow.

Delivery timeframes are estimates and may vary by product, stock location, delivery postcode, carrier availability and order timing. Wet weather, storms, flooding or unsafe site access may delay delivery and are additional to any advertised or guaranteed freight timeframes.