Frequently Asked Questions

Hot Water System FAQs

Sun City Hot Water and Plumbing are hot water specialists. From Solar pool heating to continuous flow gas hot water heaters, we do it all. We also offer servicing, repair, replacement and installation hot water system services. With years of experience in the hot water industry, you won’t find a better advice on hot water systems Brisbane and Sunshine Coast wide.

As experts when it comes to hot water, there are some questions we hear so often that we have made a page to answer them for you. If you have a question that’s not already on our page, give us a call on 1300 821 122 and we might even add it to this page!

Which hot water system should I buy?

We get this question a lot, but with hot water systems it isn’t one size fits all. There are a few questions you need to ask yourself before you will know which system is best for you.

First, How much hot water do you use at peak times? If you’re looking at a storage system the tank will need to be big enough for the maximum water used during peak times.

Next, do you need instant hot water? If you never want to run out of hot water during the day this is the best option. That being said, if your household doesn’t use much hot water it may not be necessary for you.

Lastly, what resources are available to you? Do you have gas lines connected to your house or is electricity the better option? Do you have space for the solar panels necessary for a solar hot water system?

In short, there is no simple answer to this question. There are many factors that make choosing a hot water system different for every household. Sun City are hot water specialists and can recommend the best system for you in one short phone call. If you’re looking for honest system comparisons and personalised advice, call 1300 728 122.

What size hot water system do I need?

When deciding on the size of your hot water system, there are a few factors to consider:

  1. House size (1 to 4+ occupants)
  2. Number of bathrooms (1, 2, 3+)
  3. Current water usage
  4. Climate
  5. System type: Gas, Electric Heat Pump, Solar
  6. How many outlets are used at any one time (this includes dishwasher, washing machine, and shower)
  7. Showerhead rating


How long do hot water heaters last?

The lifetime of a hot water heating system depends on the make, type and maintenance on the system. But, as a general rule:

Storage Systems: 10 to 12 years*

Tankless Systems: up to 20 years*


Why is my water heater leaking?

  1. Is it leaking near the bottom?No – Go to 2Yes – This could mean problems with the pressure relief valve or the leaking drain valve.
  2. Is the leak from the tank?Yes – This is most likely caused by damage to an internal component and almost always means your tank will need to be replaced.

For a full diagnosis and free quote call Sun City Hot Water and Plumbing on 1300 728 122

Gas vs Electric Hot Water System?

Gas (Instantaneous)



Cheaper to run

High upfront cost

No recovery time for hot water

Requires a gas connection to the house

Makes up difference in upfront cost in the first year

Smaller system – less space required

Environmentally friendly

Electric (Storage)



Low upfront cost

Expensive to run

All houses will have the required electricity connection

Limited supply of hot water

Larger system – bigger space required for installation

Less environmentally friendly

What is the most efficient solar hot water system?

There is no one solar hot water system that is considered the most efficient. However, to determine which solar hot water system will be the most efficient for you, consider:

  1. How many people you live with
  2. Average water usage of the household
  3. When are your peak water usage times
  4. The slope of your roof or the intended area for the solar collectors
  5. The area climate

For free, personalised advice on which solar hot water heating system will work best for you, call Sun City Hot Water & Plumbing on 1300 728 022 to speak with a hot water specialist.

What is the difference between storage and instantaneous hot water systems?

Gas hot water systems:


  • Heats when used
  • Small system size
  • Requires electricity
  • Minimum flow requirement (resulting in a delay in hot water)


  • Preheats for later use
  • Large storage tank
  • Water loses heat over time
  • Limited amount of hot water
  • Can be set to heat water in off-peak periods


  • Similar energy efficiency

At Sun City we work with all of the industry leaders to provide up to date advice on every system on the Australian market. Call Sun City Hot Water & Plumbing today on 1300 821 122 for advice on which hot water system is best for you.