20L Instant Gas Hot Water Systems
Shop 20L instant gas hot water systems online with Installed Today for supply-only ordering across major Australian metro areas, with supplied and installed options available on selected products in eligible Brisbane and Gold Coast service areas.
A 20L instant gas hot water system, also known as a 20L continuous flow gas hot water system, is a practical mid-size gas hot water option commonly chosen for small to medium homes, townhouses, rental properties, couples, small families and households wanting more flow capacity than a compact 16L model. Instead of storing hot water in a tank, a 20L continuous flow system heats water as it passes through the unit.
This collection is built for customers comparing natural gas and LPG 20L instant gas hot water systems for practical replacement jobs, everyday household use and moderate hot water demand. Whether you are replacing an old 20L continuous flow unit, upgrading from a 16L system, changing from gas storage, or comparing trusted brands before ordering, Installed Today makes it easier to compare product options and installation choices in one place.
Choose supply only if you already have your own licensed gas fitter or plumber arranged. Choose supplied and installed where available if you want the 20L instant gas hot water system and installation organised together in an eligible Brisbane or Gold Coast service area.
Supply Only 20L Instant Gas Hot Water Systems Across Australian Metro Areas
Supply only is ideal if you already have a licensed gas fitter or plumber ready to install your new 20L instant gas hot water system. This option suits homeowners managing their own trade, builders ordering for a project, property managers arranging a replacement, and trade customers who only need the unit supplied.
The product price is for the 20L continuous flow hot water system only. Installation, valves, old unit removal, disposal, gas work, electrical work, power point changes, pipework changes, tempering valves, drainage work, access upgrades, wall mounting changes and compliance upgrades are not included unless selected separately.
Before ordering supply only, check that the instant gas system suits the property, gas type, available gas supply, water pressure, flow rate requirements, household demand, installation location, access path and compliance requirements. This is especially important when replacing an older continuous flow unit, changing gas type, upgrading from 16L, downsizing from 26L, or changing from gas storage to continuous flow.
Supplied and Installed 20L Instant Gas Hot Water Systems in Brisbane and Gold Coast
Supplied and installed options are available on selected 20L instant gas hot water systems in eligible Brisbane and Gold Coast service areas. This option is designed for customers who want the product and installation organised together instead of buying the unit separately.
Supplied and installed can be useful when an existing 20L continuous flow system has failed, when a rental property needs a practical replacement, or when a small to medium household wants a compact external gas hot water system with more flow capacity than a 16L unit.
Availability depends on your address, existing system, gas type, installation location, site access, plumbing setup, gas supply, electrical requirements, drainage and current compliance needs. Some jobs may need additional valves, disposal, gas pipe upgrades, electrical work, pipework changes, wall mounting changes, drainage changes or compliance upgrades depending on the property.
What Is a 20L Instant Gas Hot Water System?
A 20L instant gas hot water system heats water only when a hot tap or shower is turned on. Cold water passes through the unit, the burner activates, and the water is heated as it flows through the heat exchanger.
The 20L rating refers to a nominal flow rate of 20 litres per minute under suitable conditions. This makes 20L continuous flow gas hot water systems a popular middle option between compact 16L models and larger 26L systems.
Because a 20L instant gas system does not store a full tank of heated water, it is usually compact and mounted externally on a wall. This can make it a practical choice where the home already has a similar external continuous flow unit installed, or where the customer wants a wall-mounted gas hot water replacement instead of a storage tank.
Who Should Choose a 20L Continuous Flow Gas Hot Water System?
A 20L continuous flow gas hot water system may suit small to medium homes, townhouses, units, small families, couples, rental properties, homes with one to two bathrooms and households with moderate daily hot water demand.
It can also suit customers replacing an existing 20L instant gas system that has performed well and supplied enough hot water for the property. In this case, another 20L model may be a practical replacement if the gas type, installation location and site conditions still suit.
For smaller homes or lower-use properties, a 16L continuous flow gas hot water system may be enough. For larger families, homes with multiple bathrooms, heavy back-to-back shower use or stronger peak-time demand, a 26L instant gas hot water system may be worth comparing.
Natural Gas and LPG 20L Instant Gas Hot Water Systems
20L instant gas hot water systems are commonly available in natural gas and LPG versions, depending on the brand and model. The correct gas type must be selected before ordering.
Natural gas 20L continuous flow systems are designed for properties connected to a natural gas supply. They are common in many metro areas where mains gas is available.
LPG 20L instant gas hot water systems are designed for properties using bottled LPG. These may suit homes without natural gas access, granny flats, secondary dwellings, acreage homes, rural properties and selected outdoor installations where LPG is already available.
Natural gas and LPG models are not the same. Ordering the wrong gas type can delay installation and may require product exchange or additional work. If you are unsure, check the label on your existing unit or confirm the gas type with your licensed gas fitter before ordering.
20L Instant Gas Hot Water Flow Rate Guide
A 20L instant gas hot water system is generally selected for moderate hot water demand. It can be suitable where the home needs more capacity than a compact 16L unit but does not necessarily require a larger 26L continuous flow system.
A 20L continuous flow system may be suitable for:
Small to medium homes
Townhouses and units
Couples
Small families
Rental properties
Homes with one to two bathrooms
Properties replacing an existing 20L unit
Moderate-use households
Customers wanting more flow than 16L
Compact external installation spaces
A 20L instant gas hot water system may not be suitable for:
Very large families
Homes with several bathrooms
Multiple showers running at once
High-flow shower expectations
Heavy peak-time hot water use
Regular bath filling
Properties where the old 20L unit struggled to keep up
Homes needing a stronger 26L continuous flow system
Flow rate selection depends on the number of bathrooms, number of outlets used at once, incoming water temperature, gas supply, water pressure, pipe sizing and household expectations.
20L vs 16L Instant Gas Hot Water Systems
A 16L instant gas hot water system is usually best suited to smaller homes, granny flats, units and lower-demand households. It can be practical where only one bathroom is used regularly and hot water demand is modest.
A 20L continuous flow gas hot water system provides more flow capacity and may be better suited to small to medium households, small families, rentals and townhouses where a 16L unit may be close to the limit.
If your existing 16L system has struggled during peak use, stepping up to 20L may be worth comparing. If the home has low demand and the old 16L system has performed well, staying with 16L may still be practical.
20L vs 26L Instant Gas Hot Water Systems
A 20L instant gas hot water system is a practical middle option for homes with moderate hot water demand. It can suit many small to medium households where the system is not expected to serve multiple high-use outlets at the same time.
A 26L continuous flow gas hot water system is commonly chosen for larger family homes, homes with multiple bathrooms, higher hot water demand and properties where stronger flow capacity is preferred.
A 26L system is not automatically better for every property. The gas supply, water pressure, pipe sizing and installation conditions must support the larger unit. For many smaller homes and moderate-use households, a 20L continuous flow system may be the more practical choice.
20L Instant Gas vs Gas Storage Hot Water
A 20L instant gas hot water system heats water as it flows through the unit. It is usually compact, wall-mounted and installed externally. It does not store a tank of heated water.
A gas storage hot water system heats and stores water inside a tank. It can be a practical option when replacing an existing gas storage unit and the customer wants a familiar tank-style system.
A 20L continuous flow unit may be better where the customer wants a compact external gas hot water system and the property has suitable gas supply, water pressure and installation conditions.
Gas storage may be better where the existing storage setup has worked well and the customer wants a simpler like-for-like tank replacement.
Changing from gas storage to instant gas may involve gas pipe upgrades, wall mounting, plumbing changes, electrical work, drainage changes, valve upgrades and compliance work. These extras are not included in the product price unless selected separately.
20L Instant Gas vs Electric Hot Water
A 20L instant gas hot water system uses natural gas or LPG to heat water as needed. Electric storage hot water systems use electricity to heat and store water inside a tank.
A 20L continuous flow gas system may suit homes already set up for gas hot water or properties where the customer wants a compact external gas unit. Electric storage may suit homes already set up for electric hot water and customers wanting a straightforward like-for-like electric replacement.
Changing from electric to 20L instant gas is not usually a simple product swap. The property may need gas pipework, electrical work, wall mounting, plumbing changes, valve upgrades, drainage changes and compliance work. These extras are not included in the product price unless selected separately.
Outdoor Installation for 20L Instant Gas Hot Water Systems
Most 20L instant gas hot water systems sold for standard residential replacement are external outdoor units unless the product is specifically designed and approved as an internal or flued indoor appliance.
External continuous flow systems are commonly installed on an outside wall, near an existing hot water location, beside a laundry wall, in a side passage or near an external service area. The location needs to meet clearance, ventilation, drainage, gas, water and electrical requirements.
Do not assume an external 20L instant gas system can be installed indoors. Indoor gas installations require the correct appliance type, flueing, ventilation and compliance setup. The product specifications and licensed installer should confirm suitability before ordering.
Replacing an Existing 20L Instant Gas Hot Water System
If your existing 20L instant gas hot water system has worked well, replacing it with another 20L continuous flow model can often be a practical option. This can help keep the replacement close to the existing setup, especially when the household demand has not changed.
Before choosing a replacement, check the old system’s gas type, flow rate, brand, model, installation location, water connection positions, gas connection position, electrical requirements, valve condition, drainage, access and wall mounting setup.
A replacement is also a good time to consider whether 20L is still the right size. A growing household may need a 26L continuous flow system. A smaller household may be comfortable with 16L or 20L. A rental property may prioritise a practical replacement that suits expected tenant demand.
Changing from Gas Storage to 20L Instant Gas
Changing from gas storage to a 20L instant gas hot water system may be possible, but it is not always a simple swap. A gas storage tank and a continuous flow unit have different installation requirements, connection positions and gas supply demands.
The job may require gas pipe upgrades, wall mounting, plumbing changes, electrical work, valve upgrades, drainage changes, removal of the old tank and compliance work.
Before changing system type, compare the full job requirements, not just the product price. The product price alone does not include extra gas work, electrical work, pipework changes, disposal or compliance upgrades unless selected separately.
20L Instant Gas Hot Water Brands Available
Installed Today stocks selected 20L instant gas hot water systems from trusted brands, depending on product availability. Across the broader continuous flow gas hot water range, this may include brands such as Rinnai, Rheem, Bosch and Dux.
When comparing 20L instant gas hot water systems, look beyond the brand name. Check the gas type, flow rate, warranty, dimensions, connection positions, temperature control options, outdoor installation requirements, household suitability and whether the model is a practical replacement for your existing system.
Some customers want a budget-friendly 20L replacement. Others want a premium continuous flow model, a known brand, an LPG unit, a natural gas model, or a product that closely matches the old system. The best choice depends on the property, budget and reason for replacement.
20L Instant Gas Hot Water System Buying Guide
Is a 20L instant gas hot water system enough for a family?
A 20L instant gas hot water system can suit some small families and moderate-use households, especially where the home has one to two bathrooms and hot water demand is not too heavy.
For larger families, homes with multiple bathrooms, heavy back-to-back showers or stronger flow expectations, a 26L continuous flow gas hot water system may be worth comparing.
Is a 20L continuous flow system good for a townhouse?
A 20L continuous flow gas hot water system can be a practical option for many townhouses where natural gas or LPG is available and the household has moderate hot water demand.
Townhouses can have tighter access, closer neighbouring walls and specific external mounting locations, so clearances, gas supply, water pressure, drainage and compliance requirements should be checked before ordering.
Can I replace my old 20L gas unit with the same size?
Replacing an old 20L instant gas unit with another 20L model can be practical if the old system supplied enough hot water for the property. It may also help simplify the replacement when the new system has similar connection positions and suits the same outdoor location.
However, the replacement still needs to suit the current site. Gas type, pipe sizing, water pressure, connection positions, clearances, valves, electrical supply and compliance requirements should all be checked before installation.
Should I choose 20L or 26L instant gas hot water?
Choose a 20L instant gas hot water system when the property has moderate demand, one to two bathrooms, suitable gas supply and an existing 20L system that has performed well.
Choose a 26L continuous flow system if the home needs stronger flow capacity, has a larger family, multiple bathrooms, heavier peak-time use or the old 20L system has struggled to keep up. The property’s gas supply and water pressure still need to support the selected unit.
Is 20L instant gas suitable for a rental property?
A 20L instant gas hot water system can suit many small to medium rental properties, townhouses and homes with moderate expected occupant numbers.
For smaller rentals, a 16L unit may be enough. For larger family rentals, a 26L continuous flow system may be more suitable. The best option should match tenant demand, property layout, gas type, installation location and long-term practicality.
Should I choose natural gas or LPG?
Choose natural gas if your property is connected to natural gas and the selected model is designed for natural gas. Choose LPG if your property uses bottled LPG and the selected model is designed for LPG.
Natural gas and LPG models are different, so the correct version must be ordered. If you are unsure, check the existing unit label or confirm the gas type with your licensed gas fitter.
Can a 20L instant gas system be installed indoors?
Most standard residential 20L instant gas hot water systems are external outdoor units unless the product is specifically designed and approved for indoor or flued installation.
Do not install an external gas unit indoors. Indoor gas installations require the correct appliance, flueing, ventilation and compliance setup.
What should I check before buying a 20L instant gas hot water system online?
Before buying a 20L instant gas hot water system online, check the gas type, flow rate, installation location, connection positions, clearances, water pressure, gas supply, pipe sizing, access path, drainage, electrical requirements and whether the property may need extra valves, gas work, pipework changes or compliance upgrades.
For supply only, your licensed gas fitter or plumber should confirm suitability before installation. For supplied and installed options in Brisbane and Gold Coast, the product page questions help identify common installation requirements before checkout.
Why Buy 20L Instant Gas Hot Water Systems from Installed Today?
Installed Today makes it easier to compare 20L instant gas hot water systems online by bringing selected natural gas, LPG and continuous flow gas hot water options into one collection.
You can compare trusted brands, gas types, flow rates, installation considerations and ordering options without visiting a showroom or waiting for multiple quotes just to understand your choices.
Customers choose Installed Today for supply-only ordering across major Australian metro areas and supplied and installed options on selected 20L continuous flow hot water systems in eligible Brisbane and Gold Coast service areas.
Whether you need a natural gas 20L replacement, an LPG continuous flow system, a practical gas unit for a townhouse, a rental property replacement, or a supply-only product for your own licensed installer, this collection helps you choose a 20L instant gas hot water system that suits the property, budget and household demand.
