Hot water, Brisbane style
Scale is part of the wear
Urban Utilities describes South East Queensland's water as hard to moderately hard, and says hard water can leave scale inside hot water systems. The supply serving Brisbane and Ipswich averaged 120 mg/L of hardness in 2024-25.
Big houses, smaller households
At the 2021 Census, 41.1% of Greater Brisbane homes had four or more bedrooms, while the average household was 2.6 people. When you size a new system, tell the plumber how many people shower there, not just how many bedrooms there are.
Mild winters
South-east Queensland is climate zone 2 under the building code, with warm humid summers and mild winters. The Bureau's Brisbane station averages a July minimum of 10.6°C, and a heat pump takes its heat from that outside air.
What Queensland requires
Every new and replacement hot water system here needs a temperature control device, usually a tempering valve. Stored water must be heated to at least 60°C to stop bacteria such as Legionella growing, and the state's guidance caps water at the taps at 50°C. That 50°C limit is for bathroom fixtures used for personal hygiene, not the kitchen or laundry.
Heat pumps and solar systems can only go in through a hot water installer holding the QBCC's solar and heat pump endorsement. If an electric unit's thermostat needs changing, Queensland Health says a licensed electrician should do it.
Gas units bring their own licence. Installing, repairing or servicing a gas hot water system needs a Queensland gas work licence, and some licences cover servicing only. See gas fitters in Brisbane.
Rebates and discounts
We haven't found a current heat pump or solar hot water rebate from the Queensland Government, and the state's hot water page doesn't list one. Programs open and close, so check before you buy.
Federal STCs do apply in Brisbane. Eligible heat pumps under 425 L and solar water heaters under 700 L can earn certificates, which owners usually hand to an agent for a discount on the price. Our Queensland rebates page explains more.
Which Brisbane hot water page do you need?
- Hot water repairs: no hot water, a dripping valve, or a unit that keeps tripping or going out.
- Hot water replacement: a tank leaking from its body, or a system that has had its day.
- Hot water installation: a new home, an extension, or a unit that needs to move.
- Heat pump hot water: going electric with a system that runs on outside air.
When the hot water stops in Brisbane
Rule out the supply
If the cold taps are weak too, check the pressure reduction valve. Urban Utilities says most homes built after 2005 have one, usually at the side of the house, and its blue handle is easy to knock.
Make it safe
For a leak, close the cold valve on the unit or the isolation valve at the meter. Switch an electric unit off at the switchboard; for gas, turn it off at the unit if you safely can.
Note the details
A photo of the rating plate gives the plumber the brand, model, size and age before they arrive.
Get a straight diagnosis
A hot water specialist can tell you whether it's a failed part or a failed tank, and what each option involves.
Questions for a Brisbane hot water plumber
- Which temperature control device will you fit, and is it in the quote?
- Are you endorsed by the QBCC for heat pump and solar installs?
- Is this model on the STC register, and is the discount shown on the quote?
- For a gas unit, does your gas work licence cover installation or only servicing?
- Is this notifiable work, and when will I receive my copy?
What we would do
Don't rush a replacement because the water went cold once. Get a diagnosis first, since many faults are a single part. If the tank itself is leaking, use the gap before you buy to compare a like-for-like swap with a heat pump, with the STC discount and the temperature control device spelled out on each quote. Then check the plumber's QBCC licence, or the gas fitter's gas work licence, before anyone starts.