Replacing hot water in Sydney
Sydney Water says: call a licensed plumber
Sydney Water lists replacing a hot water system, along with toilets and showers, as work for a licensed plumber rather than a weekend job. It also tells owners to ask for a Certificate of Compliance once the work is finished.
Units: heat pumps need a strata yes
With 30.7% of Greater Sydney's homes in flats or apartments, this comes up often. NSW counts installing or replacing a heat pump as a minor strata renovation: expect to supply plans, dates and the tradesperson's details, and to win more than 50% of the vote, or committee approval where a by-law allows.
Tenants go through the landlord
Greater Sydney's rental share was 35.9% at the 2021 Census. NSW Fair Trading's strata renovation guide tells tenants to write to their landlord for permission before making any changes, so if you rent, report the failure and let the owner arrange the new system.
How a Sydney replacement usually runs
Make sure it's finished
A hot water specialist checks whether the fault is a part or the tank. Water coming from the tank body itself means replacement; a failed valve or thermostat may not.
Choose the type before the quote
Like for like is fine as far as we've found. If you're moving to a heat pump or solar, ask for the Energy Savings Scheme discount and any STCs to appear as separate lines on the quote.
Sort the approvals
In a strata building, put the heat pump request to the owners corporation now. Ask your strata manager what your scheme expects for a straight swap in the same spot.
On the day
No Notice of Work is needed to replace an existing system in NSW. The plumber fits a temperature control device, even when the new unit matches the old one, so bathroom fixtures stay at 50°C or below.
Keep the certificate
The Certificate of Compliance is lodged at completion, and you're entitled to a copy as the person who arranged the work. If gas was involved, the gasfitter's certificate is separate.
Checking a discount quote
Energy NSW's published heat pump discounts, up to $640 replacing an electric water heater and up to $330 replacing gas, predate the scheme's 7 September 2026 rule change and are indicative only. The figure that counts is the one printed on your written quote.
NSW says a minimum payment toward the system and the installation is always yours, so a pitch that says you'll pay nothing doesn't fit the scheme. Ask which Accredited Certificate Provider the installer works with or is subcontracted by. Our NSW hot water discounts page goes through the rest.
Before and during the swap
You can
- Photograph the old unit's label: brand, model, capacity and manufacture date.
- If it's leaking, shut the cold water valve to the unit and switch off its power or gas, if that's safe.
- Clear a path to the unit and around where the new one will sit.
- In a strata building, tell the strata manager the booked date.
Leave to a licensed plumber
- Disconnecting and removing the old system
- Any gas connection, which needs a licensed gasfitter in NSW
- Fitting the temperature control device and setting the temperature
- Lodging the Certificate of Compliance and giving you a copy
What we would do
If the old system is still limping along, use the time. Get the strata approval or landlord sign-off sorted, decide the type, and collect quotes that each show the full price, every discount and your share. On the day, check that a tempering valve went in and that you'll receive the certificate. A system picked in a hurry on a cold morning is rarely the one you'd have chosen.