Best Hot Water System for a 1 Bathroom Home in Australia

Choosing the best hot water system for a 1 bathroom home usually comes down to four things: how many people live there, what system you already have, whether the home has gas or electric supply, and whether you want the lowest upfront cost or better long-term efficiency.

For most 1 bathroom homes, apartments, granny flats and small townhouses, a 125L or 160L electric storage hot water system is often the most practical like-for-like replacement. If the home has natural gas or LPG available, a 16L continuous flow gas hot water system can also be a strong option for compact homes that want hot water on demand. For homeowners focused on energy efficiency, a heat pump hot water system may be worth considering, especially if there is suitable outdoor space and the budget allows for a higher upfront purchase price.

The best choice is not always the biggest unit. A 1 bathroom home needs enough hot water for daily showers, kitchen use and laundry demand without overspending on a system that is larger than required.

Quick answer: what size hot water system suits a 1 bathroom home?

For a typical 1 bathroom home, these are the most common starting points:

If you are replacing an existing system and the current size has worked well, staying close to that capacity is often the simplest path. If the old system regularly ran out of hot water, the household has grown, or shower habits have changed, it may be worth stepping up in size.

You can compare current options in the Installed Today hot water systems range, including electric storage, gas, instant gas and heat pump hot water systems.

What is the best hot water system for a 1 bathroom home?

The best hot water system for a 1 bathroom home is usually the system that matches your existing setup, household size and daily usage.

For many Australian homes, that means one of these three options:

1. 125L or 160L electric storage hot water system
   Best for simple replacements, small homes, units and townhouses with existing electric storage.

2. 16L continuous flow gas hot water system
   Best for homes with natural gas or LPG where space is limited and hot water demand is moderate.

3. Heat pump hot water system
   Best for homeowners who want a more efficient electric upgrade and have suitable outdoor space.

There is no single perfect system for every 1 bathroom home. A couple in a small townhouse may be happy with a 125L or 160L electric unit, while a family with one bathroom and heavy shower use may need a larger storage tank. A single-person household may not need the same capacity as a household with teenagers, frequent guests or back-to-back morning showers.

Best overall option: 125L or 160L electric hot water system

For many 1 bathroom homes, a 125L or 160L electric storage hot water system is the easiest and most practical replacement option.

Electric storage systems are common across Australian homes because they are straightforward, reliable and available in a wide range of capacities. If the property already has an electric storage unit in the same location, replacing it with a similar size can often be simpler than changing system type.

A 125L electric hot water system can suit low-use homes, small units, granny flats and 1–2 person households. A 160L electric hot water system gives more breathing room for couples, small families or homes where showers are longer or more frequent.

You can browse current options in the electric hot water systems collection.

When a 125L electric hot water system makes sense

A 125L electric hot water system can be a good fit when the home has one bathroom and moderate daily hot water demand.

It may suit:

• 1–2 people

• Small homes, units and townhouses

• Granny flats

• Rental properties

• Homes replacing an existing 125L unit

• Properties where space is limited

• Households with normal shower lengths and no large spa bath

A 125L system is usually chosen for practicality. It gives more capacity than very small 50L or 80L units, but it does not take up as much room or cost as much as larger family-sized systems.

The main thing to watch is usage. If two people take long showers back-to-back, use hot water for laundry, or have frequent guests, a 125L unit may feel tight. In that case, a 160L or 250L system may be a better long-term choice.

When a 160L electric hot water system is better

A 160L electric hot water system is often the safer choice for a 1 bathroom home with 2 people, heavier use, or less predictable demand.

It may suit:

• Couples

• Small families with one bathroom

• Townhouses

• Renovated homes

• Homes where the old 125L system ran out too quickly

• Households with longer showers

• Properties where future resale or tenant use matters

A 160L system gives more usable capacity without jumping all the way to a larger 250L tank. For many 1 bathroom homes, it is the practical middle ground between compact size and everyday comfort.

If you are unsure whether 125L is enough, 160L is often the better size to compare first.

Should a 1 bathroom home use a 250L hot water system?

A 250L electric hot water system can be more than a small household needs, but it can still make sense in some 1 bathroom homes.

You might consider 250L if:

• 3 people live in the home

• Multiple people shower close together

• The home has high hot water usage

• The property is a rental and usage may vary

• The current 160L system often runs out

• You want more buffer for guests or future household changes

The trade-off is that a larger tank can cost more upfront, take up more space and may use more energy if the extra capacity is not needed. For a low-use 1 bathroom home, 250L may be unnecessary. For a one-bathroom family home, it may be the better choice.

You can compare smaller and larger electric units in the Installed Today hot water systems range.

Best gas option: 16L continuous flow gas hot water

If your home already has natural gas or LPG available, a 16L continuous flow gas hot water system can be a strong option for a 1 bathroom property.

Continuous flow gas systems heat water as it is needed instead of storing hot water in a tank. This makes them compact and useful for homes where space is limited. A 16L model is commonly used for small homes, apartments, townhouses and granny flats where hot water is usually needed at one shower or outlet at a time.

A 16L instant gas system may suit:

• 1 bathroom homes

• Small households

• Homes with existing gas hot water

• Townhouses and units with suitable external location

• Properties wanting a compact wall-mounted unit

• Households that want hot water on demand

You can browse options in the instant gas hot water systems collection.

Natural gas vs LPG for a 1 bathroom home

Gas hot water systems are usually available in natural gas or LPG versions. They are not interchangeable, so it is important to choose the correct fuel type for the property.

Natural gas is generally used where the home is connected to a street gas supply. LPG is used where bottled gas is supplied to the property. Before ordering a gas hot water system, check whether your home uses natural gas or LPG and choose the matching model.

For a 1 bathroom home, a compact 16L system may be enough for everyday use, but the final choice still depends on flow rate, the number of outlets used at once, gas supply, water pressure and installation requirements.

Gas systems must be installed by a licensed gas fitter. If changing from electric to gas, extra work may be required, including gas pipework, water pipework, electrical connection, drainage and compliance upgrades.

Best energy-efficient option: heat pump hot water

A heat pump hot water system can be a good option for a 1 bathroom home where long-term efficiency is a priority.

Heat pumps use electricity differently to standard electric storage systems. Instead of relying only on a traditional heating element, they draw heat from the surrounding air to help heat the water. This can make them a more efficient option for many households, especially where the system is installed in a suitable outdoor location.

A heat pump may suit:

• Homeowners replacing an older electric storage system

• Homes with suitable outdoor space

• Households wanting a more efficient electric option

• Properties using solar power during the day

• Owners planning to stay in the home long term

• Homes where the higher upfront cost can be justified by efficiency goals

For some 1 bathroom homes, a heat pump may be larger and more expensive than required. For others, it can be a smart upgrade, especially if the household wants to reduce reliance on standard electric storage.

You can compare current models in the heat pump hot water systems collection.

Electric storage vs instant gas vs heat pump for a 1 bathroom home

Here is the simple comparison:

If your existing system has worked well, replacing like-for-like is often the simplest approach. If your household needs have changed, or you are trying to improve efficiency, it may be worth comparing a different type of system before ordering.

What about instant electric hot water?

Instant electric hot water systems can suit some small-use applications, but they are not always the best whole-home solution for a 1 bathroom property.

They may be useful for small point-of-use applications, hand basins, small studios or specific low-demand setups. However, whole-home electric instantaneous systems can require significant electrical capacity and may not suit every property.

If you are replacing a standard electric storage unit in a 1 bathroom home, a 125L, 160L or suitable heat pump option is usually a more common comparison point than instant electric.

How many people can use a 1 bathroom hot water system?

The number of people a system can support depends on shower length, water temperature, shower head flow rate, climate, time of day and whether the system is storage or continuous flow.

As a general guide:

• 1 person: 80L to 125L may be enough for low to moderate use

• 1–2 people: 125L to 160L is commonly considered

• 2–3 people: 160L to 250L may be safer

• 3+ people: 250L or larger may be worth comparing, even with one bathroom

A one-bathroom home does not always mean low hot water demand. A household with three people and one bathroom may use more hot water than a two-bathroom home with one occupant. Focus on the number of people and daily habits, not just the number of bathrooms.

Questions to ask before choosing your system

Before buying a hot water system for a 1 bathroom home, ask:

• How many people live in the home?

• Does the current system run out of hot water?

• What size is the current system?

• Is the current system electric, gas, LPG, solar or heat pump?

• Is the system installed indoors or outdoors?

• Is there enough space for a larger tank or heat pump?

• Is the home connected to natural gas?

• Does the home use LPG bottles?

• Are there long showers or back-to-back showers?

• Is the property owner-occupied or a rental?

• Do you want lowest upfront cost or better efficiency?

These questions make the system choice much clearer.

Best hot water system for a small apartment or unit

For a small apartment or unit with one bathroom, space and access are often the biggest concerns.

A compact electric storage unit may be the simplest option if the property already has electric hot water. Some apartments use smaller indoor electric units, while others have outdoor or balcony-located systems depending on the building design.

A gas continuous flow system may suit some units where external installation, gas supply and building rules allow it. However, body corporate requirements, ventilation, access and compliance can limit what is possible.

For apartments and units, always check the existing system type, location and available space before ordering a replacement.

Best hot water system for a granny flat

For a granny flat, small secondary dwelling or studio, the best choice is usually compact, simple and matched to the actual number of occupants.

Common options include:

• 80L electric storage for very low-use setups

• 125L electric storage for more comfortable everyday use

• 160L electric storage where usage is higher

• 16L continuous flow gas where gas supply and external installation are suitable

The right choice depends on whether the granny flat has its own dedicated hot water system, how many people live there, and whether the system needs to support kitchen, laundry and bathroom use.

Best hot water system for a rental property with one bathroom

For a 1 bathroom rental property, reliability and tenant flexibility matter.

A 160L electric storage system is often a practical choice because it gives more capacity than a smaller 125L unit while still being suitable for many compact homes. If the property has gas, a 16L continuous flow unit may also work well.

Rental properties can be harder to size because occupant numbers and usage habits change over time. Choosing the smallest possible system may create complaints if tenants use more hot water than expected. A slightly more flexible size can be a better long-term decision.

Should you replace like-for-like?

For many 1 bathroom homes, like-for-like replacement is the easiest path.

That means replacing:

• Electric storage with electric storage

• Gas storage with gas storage

• Instant gas with instant gas

• Heat pump with heat pump

• Similar tank size with similar tank size

• Same location where practical

Like-for-like replacement can reduce complexity because the home may already have the right power, gas, water connections, drainage and space for that system type.

Changing system type can still be worthwhile, but it may involve extra checks, extra parts and additional licensed trade work.

When should you upgrade instead of replacing the same size?

You may want to upgrade if:

• Your current system runs out of hot water

• More people now live in the home

• You plan to rent out the property

• You are renovating the bathroom or laundry

• You want better energy efficiency

• The old system is undersized

• The existing system location no longer suits the home

• You are switching from electric to heat pump

• You are switching from storage to continuous flow gas

A hot water replacement is a good time to review whether the old system was actually the right system, or just the system that happened to be there.

Common mistake: buying too small

The most common mistake for 1 bathroom homes is choosing a system that is too small because the home looks compact.

A 1 bathroom home can still have high demand if:

• Multiple people shower each morning

• The shower head has a high flow rate

• Showers are long

• Hot water is used for laundry

• Guests stay often

• The property is rented

• The household has teenagers

• The system needs to recover between back-to-back use

A smaller system may save money upfront, but it can be frustrating if it regularly runs out of hot water.

Common mistake: buying too large

The opposite mistake is buying a large family-sized system for a small household that does not need it.

A larger tank may cost more, take up more room and store more hot water than the home actually uses. For a single-person household or low-use couple, a 250L or 315L storage system may be unnecessary unless there are specific usage reasons.

The best system should match the household, not just the idea that bigger is safer.

Hot water systems for 1 bathroom homes in Brisbane and Gold Coast

For eligible Brisbane and Gold Coast service areas, Installed Today offers supplied-and-installed options on selected products where available. Supply-only ordering is also available across major Australian metro areas for customers who already have their own licensed installer arranged.

For a 1 bathroom home in Brisbane or the Gold Coast, common replacement options include:

• 125L electric storage hot water systems

• 160L electric storage hot water systems

• 250L electric storage systems for higher-use homes

• 16L instant gas hot water systems

• Heat pump hot water systems for efficiency-focused upgrades

Before ordering, check the product page, available delivery options, installation availability and any required add-ons for your property.

What should be included in a proper hot water replacement?

A proper hot water replacement may involve more than simply swapping the tank.

Depending on the system and property, the order may need to account for:

• Delivery

• Correct system type and capacity

• Tempering valve requirements

• Isolation valves

• Pressure limiting valve

• Duo valve

• Drain line and safe discharge

• Electrical connection

• Gas connection for gas systems

• LPG or natural gas model selection

• Compliance updates

• Old unit disconnection

• Disposal where selected or available

• Access issues

• Stands, bases or brackets where required

Not every job needs every item. The key is to check what is included before ordering and avoid assuming that every replacement is automatically the same.

Final recommendation

For most 1 bathroom homes in Australia, start by comparing a 125L or 160L electric storage hot water system if you already have electric hot water. These sizes are practical, common and suitable for many small homes, apartments, townhouses and granny flats.

If the home has gas, compare a 16L continuous flow gas hot water system as a compact alternative. If energy efficiency is the main goal and the property has suitable space, compare a heat pump hot water system as a higher-efficiency upgrade.

The best hot water system for a 1 bathroom home is the one that gives enough hot water for the people living there without oversizing the unit or creating unnecessary installation complexity.

To compare suitable options, browse the Installed Today hot water systems range, including electric hot water systems, instant gas hot water systems and heat pump hot water systems.

Long-tail FAQs

Is a 125L hot water system enough for a 1 bathroom home?

A 125L hot water system can be enough for a 1 bathroom home with 1–2 people and moderate hot water use. If showers are long, multiple people shower back-to-back, or the property is a rental, a 160L system may be a safer option.

Is a 160L hot water system better than 125L?

A 160L system gives more capacity and flexibility than a 125L unit. It can be a better choice for couples, small families, rental properties or homes where the old system sometimes ran out of hot water.

Can a 250L hot water system be too big for a 1 bathroom home?

Yes. A 250L system may be more than a low-use 1 bathroom home needs. However, it can suit households with 3 people, long showers or higher daily demand.

What is the best gas hot water system size for a 1 bathroom home?

A 16L continuous flow gas hot water system is commonly considered for small 1 bathroom homes with moderate demand. The final choice depends on gas supply, water pressure, outlet demand and installation requirements.

Is a heat pump worth it for a 1 bathroom home?

A heat pump can be worth considering if you want a more efficient electric hot water option and have suitable outdoor space. The upfront cost is usually higher than standard electric storage, so it suits homeowners looking beyond the cheapest replacement option.

Should I choose electric or gas hot water for a 1 bathroom home?

If the home already has electric storage, replacing with electric storage is often the simplest option. If the home already has gas, instant gas may be worth comparing. Changing from one fuel type to another can involve extra work, so it should be checked before ordering.

What hot water system is best for a granny flat?

A granny flat may suit an 80L, 125L or 160L electric storage system depending on how many people live there and how much hot water they use. Where gas is available, a compact continuous flow gas system may also be suitable.

Should I replace my old hot water system with the same size?

If the old system worked well and never ran out, replacing with a similar size is often practical. If it regularly ran out, the household has grown, or the home is becoming a rental, consider stepping up in size.