Best Hot Water System for Townhouses and Duplexes

Choosing the best hot water system for a townhouse or duplex is different from choosing a system for a freestanding family home. Space is usually tighter, access can be more difficult, outdoor wall space may be limited, and the existing system location often determines what is practical.

For many townhouses and duplexes, the best hot water system is a like-for-like replacement in the correct size. That may be a 125L, 160L or 250L electric storage hot water system, a 16L to 26L continuous flow gas hot water system, or a compact heat pump hot water system where the property has suitable outdoor space and airflow.

The best option depends on the number of bathrooms, number of people in the home, existing energy source, available installation space, access, body corporate requirements and whether the property uses natural gas, LPG or electricity.

Quick answer: what hot water system suits a townhouse or duplex?

For most townhouses and duplexes, these are the most common options to compare:

A townhouse or duplex does not automatically need a smaller hot water system. Some townhouses have three bedrooms, two bathrooms and family-level demand. Others are compact homes with one or two occupants. The system should be chosen based on real usage, not just the property type.

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

What is the best hot water system for a townhouse?

The best hot water system for a townhouse is usually the system that matches the existing setup while giving enough capacity for the household.

For many townhouses, that means one of these options:

1. 125L to 250L electric storage hot water system
   Best for homes already using electric storage and needing a straightforward replacement.

2. 16L to 26L continuous flow gas hot water system
   Best for gas-connected townhouses with a suitable outdoor wall-mounted location.

3. Heat pump hot water system
   Best for homeowners wanting a more efficient electric option where outdoor space, airflow and noise placement are suitable.

The existing hot water system gives the best clue. If the current unit has worked well and is in a compliant location, replacing it with the same type and similar size is often the simplest path. If it runs out, is poorly located, or no longer suits the household, the replacement is a good opportunity to compare another size or system type.

What is the best hot water system for a duplex?

The best hot water system for a duplex depends on whether each dwelling has its own dedicated system, how many people live in each side, and where the existing units are installed.

Many duplexes use separate hot water systems for each dwelling. That means each side should be sized like its own home, not based on the whole building.

A duplex may suit:

• 125L to 160L electric storage for low-use homes

• 250L electric storage for small families

• 315L electric storage for higher-use family homes

• 16L to 26L instant gas hot water where gas supply is suitable

• Heat pump hot water where outdoor location and airflow suit

For duplexes, access and location matter. Systems may be installed down the side of the home, in a small courtyard, near a garage, on an external wall or in a shared service area. Before ordering, check the footprint, access path and whether the replacement will fit the existing space.

Best overall option: electric storage hot water

For many townhouses and duplexes, electric storage hot water is the most practical option.

Electric storage systems are common, available in a wide range of sizes and often used as direct replacements. If the property already has an electric storage system, replacing it with a similar system can reduce complexity because the power supply, water connections and location may already suit that type of unit.

Common sizes include:

• 125L electric storage for low-use homes, small townhouses and 1–2 people

• 160L electric storage for couples, small households and moderate use

• 250L electric storage for 2 bathroom townhouses and small families

• 315L electric storage for larger duplexes, families or higher demand

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

When a 125L electric hot water system makes sense

A 125L electric hot water system can suit a smaller townhouse or duplex with one bathroom and lower daily hot water demand.

It may suit:

• 1–2 people

• One bathroom properties

• Small townhouses

• Granny-flat style duplex dwellings

• Low-use rental properties

• Homes replacing an existing 125L unit

• Properties with limited space

A 125L system is compact and practical, but it may be too small if multiple people shower back-to-back, showers are long, or the property has higher tenant demand. If the current 125L system regularly runs out, consider comparing a 160L unit instead.

When a 160L electric hot water system is better

A 160L electric storage system is often a better fit for townhouses with 1–2 bathrooms and moderate demand.

It may suit:

• Couples

• Small families

• Townhouses with an ensuite and main bathroom

• Homes where the second bathroom is used occasionally

• Properties replacing an existing 160L unit

• Rentals where demand may vary slightly

A 160L system gives more buffer than a 125L unit without moving into larger family-sized tanks. For many compact townhouses, it is a practical middle ground.

When a 250L electric hot water system makes sense

A 250L electric hot water system may be the better choice for larger townhouses and duplexes with family-level demand.

It may suit:

• 3–4 people

• Two bathroom townhouses

• Small family duplexes

• Homes with back-to-back morning showers

• Properties where a 160L system is not enough

• Rentals with changing occupancy

• Homes with a bath or higher daily use

For many family townhouses, 250L is a safer comparison than a smaller 160L tank. It provides more stored hot water for morning and evening peaks while still being smaller than a large 315L or 400L family system.

Is a 315L system too big for a townhouse?

A 315L hot water system may be too large for a low-use townhouse, but it can make sense in larger properties.

It may suit:

• 4–5 people

• Larger duplexes

• Three-bedroom or four-bedroom townhouses

• Homes with teenagers

• Properties with two bathrooms used daily

• Homes where the old 250L system ran out

• Rental properties with higher occupancy

The main things to check are space, access and actual demand. A 315L system may not fit where a smaller unit was installed, and it may be more capacity than a small household needs. But for a busy family townhouse, it can be a practical choice.

Best gas option: continuous flow gas hot water

A continuous flow gas hot water system can be a strong option for townhouses and duplexes with natural gas or LPG.

These systems are compact, wall-mounted and heat water as it is needed. That makes them useful where there is limited ground space for a storage tank.

A gas continuous flow system may suit:

• Townhouses already using instant gas hot water

• Duplexes with natural gas or LPG

• Homes with limited tank space

• Properties with suitable external wall space

• Households wanting hot water on demand

• Homes replacing an existing wall-mounted gas unit

A 16L unit may suit smaller 1 bathroom homes, while a 20L or 26L model may be better for larger townhouses or two bathroom homes. The correct size depends on the number of people, number of bathrooms, gas supply, water pressure and whether multiple outlets are used at once.

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

Natural gas vs LPG in townhouses and duplexes

Gas hot water systems must be matched to the correct fuel type. Natural gas and LPG models are not interchangeable.

Natural gas is generally used where the property is connected to street gas. LPG is used where the property runs from gas bottles. Some duplexes and townhouses may have shared service arrangements, separate meters or specific body corporate rules, so it is important to confirm the setup before ordering.

If you are replacing a gas hot water system, check:

• Whether the existing unit is natural gas or LPG

• Whether the replacement model matches the fuel type

• Whether the gas supply is suitable for the new unit

• Whether the unit is external and correctly located

• Whether a licensed gas fitter has confirmed suitability

Gas systems must be installed by a licensed gas fitter. If you are changing from electric to gas, extra work may be required and should be checked before ordering.

Best efficiency option: heat pump hot water

A heat pump hot water system can be a good option for some townhouses and duplexes, but the location needs to be right.

Heat pumps use electricity to draw heat from the surrounding air and transfer it into the water. This can make them more efficient than standard electric storage in many suitable installations. However, they need outdoor airflow, clearance, drainage and noise consideration.

A heat pump may suit:

• Townhouses with suitable outdoor space

• Duplexes replacing older electric storage systems

• Owner-occupiers wanting a more efficient upgrade

• Homes with solar power

• Properties with enough room around the unit

• Homes where noise placement will not affect bedrooms or neighbours

A heat pump may not suit:

• Very tight courtyards

• Enclosed service cupboards

• Locations with poor airflow

• Areas close to bedroom windows

• Spaces with difficult condensate drainage

• Strata or body corporate sites with restrictions

You can browse available options in the heat pump hot water systems collection.

Can you install a heat pump in a townhouse?

A heat pump can be suitable for some townhouses, but it is not automatic. Townhouses often have tighter outdoor areas, shared walls, neighbours nearby and limited side access.

Before choosing a heat pump, check:

• Available outdoor space

• Airflow clearances

• Distance from bedrooms and living areas

• Noise placement

• Condensate drainage

• Access for delivery

• Electrical suitability

• Body corporate or strata rules

• Whether the selected model suits the household size

If the location is too enclosed, too close to bedrooms, or restricted by building rules, a standard electric storage or gas continuous flow system may be more practical.

Body corporate and strata considerations

Some townhouse complexes and duplex developments have body corporate or strata requirements that affect hot water replacements.

These may relate to:

• External unit location

• Appearance from common areas

• Noise

• Wall-mounted equipment

• Shared walls

• Access through common property

• Gas bottle storage

• Drainage discharge

• Working hours

• Installer access

• Approval requirements before changing system type

If you are replacing like-for-like in the same location, approval may be simpler. If you are changing to a larger tank, moving the unit, adding a heat pump, changing to gas, or altering the external appearance, check any building or body corporate rules before ordering.

Access issues in townhouses and duplexes

Access is one of the biggest practical issues for townhouse and duplex hot water replacements.

The unit may be located:

• Down a narrow side path

• Inside a garage

• In a small courtyard

• On a balcony

• In a laundry cupboard

• Behind fencing or gates

• Near a shared driveway

• In a tight service area

• Against a boundary wall

Before ordering, check whether the replacement can be safely delivered, moved into position and removed if required. Larger tanks may not fit through tight spaces. Heat pumps may need more room than the existing storage unit. Wall-mounted gas systems need suitable external mounting and clearance.

Indoor vs outdoor hot water systems

Some townhouses and duplexes have indoor electric storage systems, while others have outdoor storage tanks, external gas units or heat pumps.

The replacement needs to suit the location.

Indoor systems may need checks for:

• Safe drainage

• Overflow tray requirements

• Access

• Electrical connection

• Ventilation where relevant

• Cupboard dimensions

• Compliance with current requirements

Outdoor systems may need checks for:

• Weather exposure

• Base or slab

• Drainage

• Clearance

• Wall space

• Boundary distances

• Noise placement

• Access for service and replacement

External gas continuous flow units are designed for outdoor installation unless the model is specifically made and approved for internal/flued use. Do not assume an outdoor gas model can be installed indoors.

Should you replace like-for-like?

For townhouses and duplexes, like-for-like replacement is often the simplest and safest starting point.

This may mean replacing:

• Electric storage with electric storage

• 125L with 125L

• 160L with 160L

• 250L with 250L

• Instant gas with instant gas

• Natural gas with natural gas

• LPG with LPG

• Heat pump with heat pump

• Same location where practical

Like-for-like replacement usually reduces the chance of unexpected space, gas, electrical, drainage or approval issues. It does not mean you should ignore sizing. If the old system ran out of hot water, compare a larger size before ordering.

When should you change system type?

Changing system type may be worth considering if:

• The old system was too small

• The household has grown

• You want better efficiency

• The current location is unsuitable

• A renovation has changed the layout

• The property now has solar power

• Gas supply has become available

• You want to free up ground space

• The old system is no longer practical to replace

Changing system type can also involve extra work, including pipework, electrical upgrades, gas work, drainage, valves, wall mounting, base preparation or compliance upgrades. Always check what is included before ordering.

Electric storage vs gas continuous flow vs heat pump for townhouses

Here is a simple comparison:

For many townhouses, the existing setup will decide the easiest path. For duplexes, each dwelling should usually be assessed separately based on its own hot water demand.

Best hot water system for a small townhouse

A small townhouse with one bathroom and 1–2 occupants may suit:

• 125L electric storage

• 160L electric storage

• 16L instant gas hot water if gas is available

• Compact heat pump where outdoor space suits

The main goal is to avoid oversizing while still allowing enough hot water for daily showers, kitchen use and laundry. If the second bathroom is rarely used or the household is low-use, a smaller system may be enough.

Best hot water system for a family townhouse

A family townhouse with two bathrooms and 3–5 people may suit:

• 250L electric storage

• 315L electric storage for higher demand

• 20L to 26L instant gas hot water where suitable

• Family-sized heat pump hot water where location allows

A family townhouse should be sized more like a family home than a small unit. If several people shower each morning, or if the property has a bath, a small 125L or 160L tank may not be enough.

Best hot water system for a rental townhouse or duplex

For rental townhouses and duplexes, flexibility matters.

Tenant numbers can change, and hot water use can vary from one household to the next. A system that works for one occupant may not suit a small family later.

Common rental options include:

• 160L electric storage for low-to-moderate use

• 250L electric storage for family rentals

• 315L electric storage for larger homes

• Instant gas where the property already has suitable gas supply

For rental properties, avoid choosing the smallest system purely to reduce upfront cost. An undersized system can lead to complaints and another replacement decision sooner than expected.

Supply only vs supplied and installed

Installed Today offers supply-only ordering across major Australian metro areas for customers who already have their own licensed installer arranged. Supplied-and-installed options are available on selected products in eligible Brisbane and Gold Coast service areas where shown.

For townhouses and duplexes, it is important to check what is included before ordering. Product pricing may not include installation, valves, electrical work, gas work, pipework changes, drainage changes, access issues, old unit removal, disposal or compliance upgrades unless those items are clearly selected or included.

This matters because townhouse and duplex replacements can involve tighter access, body corporate requirements, shared spaces or restricted installation locations.

Hot water systems for townhouses and duplexes in Brisbane and Gold Coast

For eligible Brisbane and Gold Coast service areas, Installed Today offers supplied-and-installed options on selected hot water products where available.

Common options for townhouses and duplexes include:

• 125L electric storage systems

• 160L electric storage systems

• 250L electric storage systems

• 315L electric storage systems for larger properties

• 16L to 26L instant gas hot water systems

• Heat pump hot water systems where location suits

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

Common mistake: assuming a townhouse needs a tiny system

A townhouse is not always a small household. Many townhouses have two bathrooms, three bedrooms and family-level hot water demand.

A small 125L or 160L system may be fine for one or two people, but it may struggle in a family townhouse. Choose the system based on people, showers and daily routines, not just the building type.

Common mistake: ignoring body corporate rules

If a townhouse is part of a complex, body corporate or strata rules may affect where a system can be installed or whether the external appearance can change.

This is especially important when changing from a storage tank to a wall-mounted gas unit, adding a heat pump, relocating a system, or placing equipment near common areas.

Check approval requirements before ordering if the replacement is not a straightforward like-for-like swap.

Common mistake: choosing heat pump without checking airflow

Heat pumps need space and airflow. A tight townhouse courtyard, enclosed side path or small service area may not be suitable.

If a heat pump cannot breathe properly, is too close to bedrooms, or has nowhere to discharge condensate, it may not be the best option. In that case, electric storage or instant gas may be more practical.

Common mistake: ordering gas without confirming fuel type

A gas hot water system must match the property’s fuel type. Natural gas and LPG are different, and the wrong model cannot simply be used in place of the correct one.

Before ordering, confirm whether the property uses natural gas or LPG. This is especially important for duplexes, townhouses with gas bottles, and properties with shared or unusual gas arrangements.

Final recommendation

For most townhouses and duplexes, the best hot water system is a correctly sized like-for-like replacement. If the property already has electric storage, compare 125L, 160L, 250L or 315L electric storage systems depending on household size and bathroom use. If the property has gas, compare a 16L to 26L continuous flow gas hot water system matched to natural gas or LPG. If efficiency is the main goal and the property has suitable outdoor space, compare a heat pump hot water system.

The key is to balance capacity, space, access and compliance. Townhouses and duplexes can have tighter installation conditions than freestanding homes, so the simplest-looking upgrade is not always the most practical.

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

What size hot water system do I need for a townhouse?

A small townhouse may suit a 125L or 160L electric storage system, while a larger family townhouse may need 250L or 315L. The right size depends on the number of people, bathrooms, shower habits and whether the current system runs out.

What is the best hot water system for a duplex?

The best hot water system for a duplex depends on each dwelling’s size and usage. Many duplexes suit 160L to 250L electric storage, instant gas where gas is available, or heat pump hot water where outdoor space and airflow suit.

Is instant gas hot water good for townhouses?

Instant gas hot water can be good for townhouses with suitable natural gas or LPG supply and an external wall-mounted location. The system must be correctly sized and installed by a licensed gas fitter.

Can a townhouse have a heat pump hot water system?

A townhouse can have a heat pump hot water system if there is suitable outdoor space, airflow, drainage, access and acceptable noise placement. Some townhouse complexes may also have body corporate rules that need to be checked.

Is a 125L hot water system enough for a townhouse?

A 125L system may be enough for a low-use townhouse with 1–2 people and one bathroom. For families, long showers or two bathroom homes, 160L, 250L or larger may be better.

Should I replace my townhouse hot water system with the same type?

If the current system has worked well and the location is suitable, replacing with the same type and similar size is often the simplest option. If it runs out or no longer suits the household, compare a different size or system type before ordering.

Do duplexes need separate hot water systems?

Many duplexes have separate hot water systems for each dwelling. Each side should be sized based on its own occupants, bathrooms and usage rather than the whole building.

What should I check before ordering hot water for a townhouse?

Check the current system type, size, location, access, available space, gas type if applicable, electrical requirements, drainage, body corporate rules and whether you need supply only or supplied and installed.