Best Hot Water System for Apartments and Units

Choosing the best hot water system for an apartment or unit is different from choosing one for a freestanding house. Space is tighter, access can be harder, body corporate rules may apply, and the existing hot water system location often limits what can be replaced easily.

For most apartments and units in Australia, the best hot water system is usually a like-for-like replacement that matches the existing setup. That may be a small electric storage hot water system, a 125L or 160L electric storage system, or in some properties, an instant gas hot water system where the unit is already set up for gas and the installation location is suitable.

A heat pump can be suitable for some apartments and units, but only where there is proper outdoor space, airflow, drainage and approval. It should not be assumed as a simple replacement for every apartment.

Quick answer: what hot water system suits an apartment or unit?

For most apartments and units, these are the common options to compare:

The safest starting point is to check the existing hot water system type, size, location and access. In apartments and units, replacing like-for-like is often much simpler than changing system type.

You can compare current 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 an apartment?

The best hot water system for an apartment is usually the one that fits the existing space and meets the household’s daily demand without requiring unnecessary building changes.

For many apartments, this means:

1. Small electric storage hot water system
   Best for studios, small units and indoor cupboard locations.

2. 125L or 160L electric storage hot water system
   Best for 1–2 bedroom apartments with more regular daily use.

3. Instant gas hot water system
   Best only where the apartment already has suitable gas hot water infrastructure.

4. Heat pump hot water system
   Best only where outdoor space, airflow, drainage, noise and body corporate approval are suitable.

The existing system matters. If the apartment has an indoor electric storage unit in a cupboard, replacing it with a similar electric unit may be the most practical option. If the apartment already has an external gas unit, a matched gas replacement may be practical. If the apartment has no suitable outdoor space, a heat pump may not be realistic.

What is the best hot water system for a unit?

The best hot water system for a unit depends on whether the unit is a small apartment-style property, a ground-floor unit, or a villa-style unit with outdoor service space.

A unit may suit:

• 50L to 80L electric storage for very low-use properties

• 125L electric storage for small 1–2 person homes

• 160L electric storage for couples or moderate use

• 250L electric storage for larger units or small families

• Existing instant gas replacement where the property already supports gas

• Heat pump hot water only where the outdoor location is suitable

Ground-floor units may have more flexibility than high-rise apartments because they may have courtyards, garages, laundries or outdoor service areas. High-rise apartments are often more restricted by space, access, drainage and body corporate rules.

Best overall option: electric storage hot water

For many apartments and units, electric storage hot water is the most practical option.

Electric storage systems are common in apartments because they can be installed in compact spaces, cupboards, laundries, garages or external service areas depending on the building design. They are also available in smaller capacities, which can suit low-use households.

Common apartment and unit sizes include:

• 50L electric storage for very low-use point-of-use applications

• 80L electric storage for small studios or low-demand homes

• 125L electric storage for 1–2 people

• 160L electric storage for 1–3 people or moderate use

• 250L electric storage for larger units or family-style properties

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

When a 50L or 80L electric hot water system makes sense

A 50L or 80L electric hot water system may suit a very small apartment, studio, office-style unit, granny flat or low-use property.

It may be suitable where:

• Only one person lives in the home

• The shower use is light

• Space is very limited

• The existing unit is already 50L or 80L

• The system only services a small area

• The property has very low hot water demand

These compact systems are useful where space is the main constraint, but they can run out quickly if used for regular showers, laundry and kitchen demand. If two people live in the unit, or shower use is higher, a 125L system may be a better comparison.

When a 125L electric hot water system is better

A 125L electric hot water system is often a good fit for a small apartment or unit with 1–2 people.

It may suit:

• 1 bedroom apartments

• Small 2 bedroom units

• Couples with moderate hot water use

• Low-use rental properties

• Compact homes replacing an existing 125L unit

• Properties where 80L is not enough

A 125L system gives more comfort than very small units without taking up as much space as a larger family system. For many apartments, it is a practical middle ground.

The main risk is undersizing. If two people take long showers, or if the unit has a bath, a 125L system may not be enough. In that case, a 160L system may be worth comparing.

When a 160L electric hot water system makes sense

A 160L electric storage system can suit larger apartments, small families, couples with higher use, and rental units where demand may vary.

It may suit:

• 2 bedroom units

• 2–3 people

• Apartments with regular shower use

• Homes where the old 125L system ran out

• Small families

• Rental properties

• Units with more space for a larger cylinder

A 160L system provides more stored hot water than a 125L unit while still being smaller than common family-sized systems. It can be a good choice where comfort matters but space is still limited.

Is a 250L system too big for an apartment?

A 250L hot water system is too large for many apartments, but it can suit some larger units, villa-style units, ground-floor properties or small family homes.

It may make sense if:

• 3–4 people live in the unit

• The property has two bathrooms

• The unit has a bath

• The existing system is already 250L

• There is enough physical space

• Access for delivery and replacement is practical

• The old 160L system regularly ran out

It may not make sense if:

• The property is a small studio

• Only one person lives there

• The system is in a tight cupboard

• Access is restricted

• The extra capacity is not needed

• Body corporate restrictions apply

Before ordering a larger system, always check dimensions, access and whether the location can handle the size and weight.

Best gas option: like-for-like instant gas replacement

Some apartments and units use gas hot water, especially where the building has existing natural gas or LPG arrangements and compliant external or flued installation locations.

An instant gas hot water system may suit:

• Apartments already using instant gas hot water

• Units with existing gas supply

• Properties with a compliant external unit location

• Homes replacing a similar gas model

• Ground-floor units or townhouse-style units with outdoor wall space

• Properties where the correct natural gas or LPG model is selected

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

Can you install instant gas hot water in an apartment?

Instant gas hot water can work in some apartments, but it is not suitable for every building.

Important checks include:

• Whether the building has natural gas or LPG

• Whether the current unit is already gas

• Whether the system is external or internal/flued

• Whether the replacement model matches the location

• Body corporate rules

• Flue and ventilation requirements

• Clearances from windows, doors and balconies

• Gas pipe sizing

• Access for installation and servicing

External gas hot water units are designed for outdoor installation unless the manufacturer specifically provides an approved internal/flued model. Do not assume an outdoor gas unit can be installed indoors or in an enclosed cupboard.

Gas systems must be installed by a licensed gas fitter.

Natural gas vs LPG in apartments and units

Gas hot water systems must match the property’s fuel type. Natural gas and LPG models are not interchangeable.

Natural gas is usually supplied by a street gas connection or building gas infrastructure. LPG is generally supplied by bottles or a dedicated LPG setup. Some units and apartments may have shared services, individual meters or body corporate rules that affect replacement choices.

Before ordering a gas system, confirm:

• Whether the property uses natural gas or LPG

• Whether the existing system label shows the fuel type

• Whether the replacement model is the same fuel type

• Whether the gas supply is suitable for the chosen unit

• Whether installation is allowed in the current location

Choosing the wrong gas type can delay the job and create compliance issues.

Can apartments use heat pump hot water?

Some apartments and units can use heat pump hot water, but many cannot.

A heat pump may be possible where the property has:

• Suitable outdoor space

• Good airflow

• Enough clearance around the unit

• Drainage for condensate

• Acceptable noise placement

• Access for delivery and installation

• Electrical suitability

• Body corporate or strata approval where required

A heat pump may be difficult or unsuitable where the system is:

• Inside a cupboard

• In an enclosed laundry

• On a small balcony with poor airflow

• Near bedroom windows

• Close to neighbours

• In a restricted service area

• In a high-rise building without suitable outdoor plant space

Heat pumps need to breathe. They are not usually a simple swap for a small indoor electric storage unit unless the property has a suitable location.

Heat pump vs electric storage for apartments

Here is the simple comparison:

For most apartment replacements, electric storage is often the practical starting point. Heat pump hot water is worth comparing only when the property has a suitable location and approval path.

Indoor hot water systems in apartments

Many apartments have indoor electric storage systems located in cupboards, laundries, hallway cupboards or under-benchtop spaces.

Indoor replacements need careful checking for:

• System dimensions

• Access to remove the old unit

• Safe drainage

• Overflow tray requirements

• Valve access

• Electrical connection

• Doorway and cupboard clearances

• Weight and floor support

• Compliance with current requirements

A new system may not be identical in shape or connection location, even if the capacity is similar. Always check dimensions before ordering.

Outdoor hot water systems in units

Some ground-floor units and villa-style units have hot water systems outside, often down the side of the property, in a courtyard, beside a garage or near a laundry wall.

Outdoor systems may give more options, including larger electric storage, gas continuous flow or selected heat pump systems. However, outdoor installations still need checks for:

• Base or slab

• Weather exposure

• Drainage

• Access

• Clearance

• Wall space

• Noise placement

• Body corporate rules

• Boundary restrictions

• Visibility from common areas

Outdoor space does not automatically mean every system will fit. Heat pumps and larger tanks may need more room than the existing unit.

Body corporate and strata considerations

Apartments and units often have body corporate or strata rules that affect hot water replacements.

These may cover:

• External equipment appearance

• Balcony installations

• Noise limits

• Common property access

• Working hours

• Drainage discharge

• Gas bottle storage

• Wall-mounted equipment

• Penetrations through walls

• Flue locations

• Installer parking and lift access

• Approval for changing system type

A like-for-like replacement in the same location may be easier to approve than moving the unit or changing system type. If you are unsure, check with the building manager, strata manager or body corporate before ordering.

Access issues in apartments and units

Access is a major part of apartment hot water replacement.

Before ordering, check:

• Lift access

• Stair access

• Parking access

• Distance from delivery area

• Narrow hallways

• Cupboard dimensions

• Whether doors need to be removed

• Whether the old unit can be removed safely

• Whether the replacement unit fits through the path

• Working hours allowed by the building

A larger replacement system may not fit through the same access path as expected. This is especially important in older units, high-rise buildings and tight internal cupboard locations.

Should you replace like-for-like?

For apartments and units, like-for-like replacement is often the best starting point.

This may mean replacing:

• Electric storage with electric storage

• 80L with 80L

• 125L with 125L

• 160L with 160L

• Instant gas with instant gas

• Natural gas with natural gas

• LPG with LPG

• Same location where practical

Like-for-like replacement can reduce the need for approvals, extra trades or building changes. However, if the old system was too small, unreliable or regularly ran out of hot water, compare whether a slightly larger unit can fit.

When should you change system type?

Changing system type may be worth considering if:

• The current system runs out too often

• You are renovating the unit

• The old location is no longer practical

• You want a more efficient option

• The property has outdoor space for a heat pump

• The apartment already has gas infrastructure

• The building allows the change

• The extra work and approvals are manageable

Changing system type may also involve electrical upgrades, gas work, pipework changes, drainage changes, wall penetrations, body corporate approval or additional compliance requirements. These should be checked before ordering.

Best hot water system for a studio apartment

A studio apartment may suit a smaller electric storage system if hot water use is low.

Common options include:

• 50L electric storage for very light use

• 80L electric storage for a single occupant

• 125L electric storage where daily shower use is higher

A studio usually does not need a large family-sized system, but undersizing can still be a problem if the occupant takes long showers or the system also services kitchen and laundry use.

Best hot water system for a 1 bedroom apartment

A 1 bedroom apartment often suits an 80L to 125L electric storage system, depending on the number of occupants and shower habits.

A single occupant may be comfortable with a smaller system. A couple may prefer 125L for more buffer. If the existing 80L system regularly runs out, compare whether a 125L unit can fit in the available space.

Best hot water system for a 2 bedroom unit

A 2 bedroom unit may suit a 125L or 160L electric storage system in many cases.

A 125L system may suit 1–2 people with moderate use. A 160L system may be better for couples, small families, rentals or properties where the second bedroom is regularly occupied.

If the unit has two bathrooms or a bath, compare 160L or larger options depending on space and access.

Best hot water system for a rental apartment

For rental apartments, reliability and predictable capacity matter.

A rental apartment may suit:

• 80L electric storage for low-use studios

• 125L electric storage for 1 bedroom apartments

• 160L electric storage for 2 bedroom units

• Larger systems only where space and demand justify it

• Like-for-like instant gas where the existing setup is already gas

Rental usage can change between tenants, so choosing the smallest possible unit may create complaints later. If space allows, a slightly more flexible size can be a better long-term decision.

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 apartments and units, always check what is included before ordering. Product pricing may not include installation, valves, electrical work, gas work, pipework changes, drainage changes, lift access issues, stairs, old unit removal, disposal or compliance upgrades unless those items are clearly selected or included.

Apartment jobs can have extra access requirements, building rules and approval steps, so the cheapest product price is not always the full picture.

Hot water systems for apartments and units 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 apartments and units include:

• 50L electric storage systems

• 80L electric storage systems

• 125L electric storage systems

• 160L electric storage systems

• 250L systems for larger units where space allows

• Like-for-like instant gas systems where suitable

• Heat pump systems only where location and approval suit

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

Common mistake: ordering a larger unit without checking the cupboard

Apartment hot water systems are often installed in tight cupboards. A larger replacement may not fit, even if the capacity sounds better.

Before choosing a larger system, check:

• Height

• Width

• Depth

• Door opening

• Pipe location

• Valve access

• Drainage

• Electrical access

• Space to remove the old unit

• Space to install and service the new unit

A 160L system may be a better size on paper, but if only a 125L unit fits safely, the location may decide the choice.

Common mistake: assuming heat pump is always possible

Heat pump hot water can be efficient, but many apartments do not have the right location.

A heat pump needs airflow, outdoor space, condensate drainage, clearance and noise consideration. It may also need body corporate approval. If the existing system is inside a cupboard or laundry, a heat pump is unlikely to be a simple swap.

Common mistake: choosing gas without checking flue and location

Gas hot water in apartments can be more complex than in freestanding homes.

Before choosing gas, check whether the property already has gas hot water, whether the unit is external or internal/flued, and whether the replacement model suits the location. External gas units should not be installed indoors unless the model is specifically designed and approved for that type of installation.

Common mistake: ignoring body corporate requirements

Body corporate rules can affect external units, heat pumps, gas systems, balcony equipment, noise and access through common property.

If you are replacing like-for-like in the same location, the process may be easier. If you are changing system type, moving the unit or adding visible equipment, check requirements before ordering.

Final recommendation

For most apartments and units, the best hot water system is a correctly sized like-for-like electric storage replacement. A small studio may suit 50L to 80L, a 1 bedroom apartment may suit 80L to 125L, and a 2 bedroom unit may suit 125L to 160L. Larger units or family-style properties may need 250L or more, but only where space and access allow.

If the property already has suitable gas infrastructure, a like-for-like instant gas replacement may be practical. If the unit has suitable outdoor space, airflow, drainage and body corporate approval, a heat pump may be worth comparing as an efficiency-focused option.

The best hot water system for an apartment or unit is not just about capacity. It must fit the space, suit the building rules, match the existing services and provide enough hot water for the people living there.

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 an apartment?

A studio may suit 50L to 80L, a 1 bedroom apartment may suit 80L to 125L, and a 2 bedroom unit may suit 125L to 160L. Larger units may need 250L where space and demand justify it.

Is a 125L hot water system enough for an apartment?

A 125L system can be enough for many 1 bedroom or small 2 bedroom apartments with 1–2 people. If the household has long showers, higher demand or more occupants, a 160L system may be worth comparing.

Can I put a heat pump hot water system in an apartment?

A heat pump may be possible in some apartments with suitable outdoor space, airflow, drainage and body corporate approval. It is usually not a simple replacement for an indoor cupboard electric storage unit.

Is instant gas hot water suitable for apartments?

Instant gas hot water can suit apartments that already have the correct gas infrastructure, flue or external location, and approval. It must be the correct natural gas or LPG model and installed by a licensed gas fitter.

What is the best hot water system for a small unit?

A small unit may suit an 80L, 125L or 160L electric storage system depending on the number of occupants and daily hot water use. The existing system size and location are usually the best starting points.

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

If the current system has worked well and fits the space, replacing with the same size can be practical. If it regularly runs out, compare a larger size, but check cupboard dimensions, access and building rules first.

Can I install a larger hot water system in an apartment?

You may be able to install a larger system if there is enough space, access, drainage and electrical suitability. In many apartments, cupboard size and building rules limit the replacement options.

Do I need body corporate approval to replace apartment hot water?

A like-for-like replacement in the same location may be simpler, but body corporate approval may be needed if you change system type, move the unit, add external equipment, alter drainage or affect common property.