You have been told that your hot water system needs replacing, so you contact a few local installers and ask for quotes.
One quote seems surprisingly affordable. Another is significantly higher. A third recommends a completely different type of hot water system.
At first glance, it can look like three businesses are charging very different prices for the same job. In reality, they may not be quoting the same solution at all.
The cost of replacing a hot water system is not determined by the price of the tank alone. The correct system, the condition of the existing installation, the available energy supply and the amount of work required at the property can all affect the final quote.
Before choosing the cheapest option, it is important to understand exactly what each installer is recommending and why.
A Hot Water Quote Is More Than the Price of the Unit
A replacement quote normally includes two broad components:
- The hot water system itself
- The work required to install it safely and correctly
The second component is where much of the variation occurs.
A straightforward replacement may involve removing an old unit and installing a similar system in the same location. A more complicated replacement could require new valves, pipework, electrical work, gas modifications, drainage improvements or relocation of the system.
Two quotes can therefore include very different amounts of labour and supporting work, even when the systems appear similar.
Is the Quote for a Like-for-Like Replacement?
The simplest option is often to replace the existing hot water system with another unit of the same type and approximately the same size.
For example, an old electric storage system may be replaced with a newer electric storage system in the same position.
This can reduce the amount of installation work required, but it does not automatically mean it is the best long-term choice.
The existing system may have been:
- Too small for the household
- Larger than the household actually needs
- Expensive to operate
- Poorly positioned
- Unsuitable for the property
- Selected before the household’s needs changed
A family may have grown since the original system was installed. Alternatively, children may have moved out and the household may no longer require such a large storage tank.
A proper replacement assessment should consider how the home is used now, rather than automatically copying a decision made many years ago.
Different Quotes May Recommend Different System Types
One installer may recommend electric storage. Another may suggest a heat pump. A third may believe gas or solar hot water is more appropriate.
These are not interchangeable products. They have different purchase prices, installation requirements, operating characteristics and expected running costs.
The main options available to many Brisbane homeowners include:
- Electric storage hot water systems
- Heat pump hot water systems
- Gas storage hot water systems
- Continuous-flow gas hot water systems
- Solar hot water systems
There is no single system type that is automatically best for every property.
The right recommendation depends on the number of people in the home, when hot water is used, the available space, the existing plumbing, the electrical supply, access to gas and the homeowner’s priorities.
A lower-cost system may be appropriate for one household but expensive to operate in another. A more efficient system may offer long-term savings, but only when it is suitable for the property and installed correctly.
The Size and Recovery Rate of the System Matter
Two hot water systems can look similar while providing very different performance.
Storage capacity is important, but it is not the only measurement that matters. The system’s recovery rate determines how quickly it can heat replacement water after hot water has been used.
An undersized system may leave the household running out of hot water. An unnecessarily large system can cost more to purchase and may use more energy maintaining water at temperature.
The installer should consider factors such as:
- The number of people living in the home
- The number of bathrooms
- Whether showers are commonly used at the same time
- The household’s morning and evening routines
- Bath usage
- Dishwasher and washing machine connections
- Future changes to the household
A quote based only on the capacity of the existing tank may overlook the household’s actual hot water demand.
Existing Valves and Pipework May Need Attention
A replacement hot water system must connect to the existing plumbing infrastructure, but that infrastructure may not always be in suitable condition.
Older installations can contain worn valves, corroded fittings, inappropriate materials or pipework that no longer meets the requirements of the new system.
The quote may need to allow for items such as:
- Pressure-limiting or pressure-reduction valves
- Tempering valves
- Isolation valves
- Non-return valves
- Relief valve drainage
- Replacement pipework
- Insulation around exposed hot water pipes
One quote may include replacing these components while another assumes they can be reused.
This does not necessarily mean the higher quote is overpriced. It may mean the installer has identified work that is required for the new system to operate properly.
Changing System Types Can Require Additional Work
Moving from one form of hot water to another can provide benefits, but it may involve more than replacing the physical unit.
For example, changing from gas hot water to an electric or heat pump system may require:
- Electrical assessment or circuit upgrades
- Changes to the existing gas service
- Alterations to pipework
- A new installation position
- Drainage for heat pump condensate
- A suitable base for the new system
Changing from electric storage to continuous-flow gas may require an adequate gas supply and a suitable location for the unit.
These changes can increase the upfront installation cost, even when the new system may be better suited to the household over time.
The Installation Location Can Affect the Quote
A system located beside the driveway with clear access will generally be easier to replace than one positioned under a house, behind a narrow fence or inside a confined area.
Access can affect the labour, equipment and number of people required to complete the work.
The location can also influence whether the new unit can remain in the same position.
An installer may recommend relocating the system to:
- Improve servicing access
- Reduce the distance hot water travels through the home
- Provide better airflow for a heat pump
- Meet clearance requirements
- Improve drainage
- Protect the system from damage
- Reduce noise near bedrooms or neighbouring properties
A quote that includes relocation will naturally differ from one based on leaving the unit exactly where it is.
Removal and Disposal May Not Be Included
Homeowners should confirm whether the quote includes disconnecting, removing and disposing of the old hot water system.
Storage tanks can be large, heavy and difficult to move, especially when access is restricted.
Some quotes include disposal as part of the complete replacement. Others may list it separately or leave responsibility with the homeowner.
This is one reason it is important to compare the inclusions rather than only comparing the total figures at the bottom of each quote.
Brand, Warranty and Ongoing Support Affect the Price
Not every hot water system is built to the same standard or supported in the same way.
Two systems with similar capacities can have different:
- Tank materials
- Components
- Warranty periods
- Efficiency ratings
- Noise levels
- Recovery performance
- Parts availability
- Manufacturer support
A cheaper unit may still be appropriate in some circumstances, but homeowners should know what they are purchasing and what happens if the system develops a fault.
It is also worth asking whether the installer will assist with a warranty issue or whether the homeowner will need to deal directly with the manufacturer.
Does the Quote Include Everything Required?
When comparing hot water system quotes, ask whether each quote includes:
- The recommended hot water system
- Delivery of the new unit
- Removal and disposal of the old unit
- Required valves and fittings
- Pipework alterations
- A suitable system base
- Electrical or gas work where required
- Testing and commissioning
- Cleaning the work area
- Manufacturer and installation warranty information
A short quote with a single total may be difficult to compare with a detailed quote that clearly explains the proposed work.
Ask questions when something is unclear. A reputable installer should be able to explain why a particular system has been recommended and what is included in the price.
Questions to Ask Before Accepting a Hot Water Quote
Before making a decision, consider asking the installer:
- Why have you recommended this particular system?
- Is it sized for the way our household uses hot water?
- Are there other suitable system types we should consider?
- What work is included in the quoted price?
- Could additional costs arise once the old unit is removed?
- Are the existing valves and pipework being reused?
- Does the quote include disposal of the old system?
- What warranty applies to the unit and the installation?
- Who should we contact if the system develops a problem?
The installer’s answers can reveal much more than the final price.
The Cheapest Quote Is Not Always the Cheapest Outcome
Choosing the cheapest quote can make sense when it provides the correct system and includes all required work.
The risk arises when the lower price is achieved by installing an unsuitable system, excluding necessary work or simply replacing the previous unit without investigating whether it met the household’s needs.
An incorrectly sized or poorly selected system can result in:
- Running out of hot water
- Higher energy bills
- Poor water pressure or temperature performance
- Additional repair costs
- The need to replace the system earlier than expected
The goal should not be to find the most expensive system. It should be to identify the most appropriate complete solution for the home.
Get the Right Hot Water System for Your Home
RJT Plumbing & Gas assesses the household, the existing installation and the available system options before recommending a replacement.
Depending on the property, the right answer may be a straightforward like-for-like replacement. In other situations, changing the system type, capacity or installation location may provide a better long-term result.
Our hot water system calculator can help you explore the available options, but an on-site assessment allows us to consider the details that an online estimate cannot see.
If your hot water system has failed, is running out too quickly or is becoming increasingly expensive to operate, contact RJT Plumbing & Gas for practical advice and a clear replacement quote.
Frequently Asked Questions
Why do hot water system replacement quotes vary so much?
Hot water replacement quotes can vary because they may include different systems, tank sizes, brands, installation requirements and supporting work. One quote may cover a straightforward like-for-like replacement, while another may include new valves, pipework, electrical work, gas modifications, system relocation or removal of the old unit.
Is the cheapest hot water system quote always the best option?
Not necessarily. A cheaper quote may be suitable when it includes the correct system and all required installation work. However, a low quote may also be based on reusing old components, excluding disposal or installing a system that does not properly suit the household's hot water requirements.
What should be included in a hot water system replacement quote?
A complete quote should clearly state the recommended system, delivery, installation, required valves and fittings, pipework changes, testing, commissioning and warranty information. Homeowners should also confirm whether removal and disposal of the old system, electrical work, gas work or a new system base are included.
Should I replace my hot water system with the same type?
A like-for-like replacement can be the simplest option, but it is not always the best long-term choice. The existing system may be incorrectly sized, expensive to operate or unsuitable for the household's current needs. It is worth comparing electric storage, heat pump, gas and solar options before making a decision.
How is the correct hot water system size calculated?
The correct size depends on the number of people in the household, the number of bathrooms, showering habits, peak hot water usage, bath usage and the system's recovery rate. Tank capacity alone does not determine whether a system will provide enough hot water.
Can changing hot water system types increase installation costs?
Yes. Changing from gas to electric, electric storage to heat pump or another system type can require additional plumbing, electrical work, gas disconnection, drainage, relocation or a new installation base. These changes can increase the upfront cost while potentially providing a better long-term solution.
Does the location of a hot water system affect the quote?
Yes. Systems installed in narrow, enclosed or difficult-to-access areas can require additional labour and equipment. The new system may also need to be relocated to improve access, drainage, airflow, servicing or the distance hot water travels through the home.
Do hot water replacement quotes include disposal of the old tank?
Some quotes include removal and disposal of the old system, while others list it separately or exclude it. Homeowners should confirm this before accepting a quote, particularly when the existing tank is large, heavy or difficult to access.
