Two numbers, not one
Every hot water quote is really two things added together: the price of the unit, and the price of putting it in. They move independently. A cheap electric tank in an awkward position can cost more installed than a mid-range gas unit swapped straight onto an existing bracket.
The figures below are the ranges published by the business for Western Australian supply, and they are unit prices before installation.
Unit prices by system type
| System type | Typical minimum | Typical maximum |
|---|---|---|
| Electric — storage | $450 (25L) | $1,800 (400L) |
| Electric — instantaneous | $660 | $1,300 |
| Gas — storage | $850 (135L) | $1,500 (360L) |
| Gas — instantaneous | $750 | $1,600 |
| Solar — roof mounted, electric boost | $3,600 | $4,400 |
| Solar — split system, electric boost | $3,900 | $5,000+ |
| Solar — split system, gas boost | $4,900 | $6,500+ |
| Solar — evacuated tube | $4,000 | $5,500 |
| Heat pump | $3,300 (160L) | $4,000 (315L) |
Prices move with brand, capacity and the market, so treat these as a bracket to sanity-check a quote against rather than a fixed price list. Ask for a written quote before any work starts.
Installation costs
Installation is where quotes diverge most, and it comes down to how much has to change.
Straight replacement, same type, same position. Roughly $220 to $660. This assumes the existing base, connections, electrical or gas supply and relief drain are all serviceable. If additional valves are required, or the plumbing or electrical work needs upgrading, it lands higher.
Repositioning the unit. Another $1,000 to $2,000 on top, depending on how far it moves and what plumbing and electrical work follows it. Moving a unit off a front elevation or out of a cramped alcove sits in this band.
Changing energy type. In the order of $1,500 to $3,000. Electric to gas is the common one: a new gas point, flue clearances, and decommissioning the old electrical supply.
Upsizing. If you are going from a 160 litre to a 315 litre tank, expect additional plumbing and possibly electrical work, plus a base capable of carrying the extra weight.
Solar sits outside these bands because roof work and collector mounting are their own exercise. The solar hot water page explains what drives that.
The line items worth checking
A quote that looks low is often a quote that excludes things. Before comparing, confirm each of these is either included or priced:
- Removal and disposal of the old unit
- Tempering valve, if the existing installation does not have a compliant one
- Pressure and temperature relief valve and a correctly run drain line
- Cold water expansion control valve
- Base, stand or wall bracket replacement where the old one has corroded
- Electrical isolation or gas disconnection of the redundant supply
- Notice of Completion lodgement by the licensed plumbing contractor
Coastal Mandurah adds one more: corroded bases and brackets are common within a couple of kilometres of the ocean and the estuary, and they are found when the old unit comes off, not from the driveway. The installation page covers that in more detail.
Cheapest to buy is not cheapest to own
An electric storage tank wins the purchase price comparison and loses the ten-year one, because resistive heating is the most expensive way to make hot water on a standard WA tariff. A heat pump costs several times more upfront and uses roughly a third of the electricity. Gas sits in between if you are on the mains network, and well behind if you are on bottled LPG.
Work out which side of that trade-off your household is on before you shortlist units — the system selection guide runs through it, and the electric hot water page covers where a plain tank still makes sense.
For a written quote on your property anywhere in the Mandurah and Peel service area, call (08) 9516 1934.
Frequently asked questions
Why do two quotes for the same hot water system differ by hundreds of dollars?
Usually because they include different things. Check whether each quote covers removal and disposal of the old unit, a new tempering valve, a new relief valve and drain line, any base or bracket work, and the electrical or gas disconnection. A cheap headline price with those items excluded is not cheaper once they are added back.
Should I buy the unit myself and pay a plumber to fit it?
It rarely saves money and it complicates the warranty. Trade pricing on hot water units is generally better than retail, and manufacturers frequently tie their warranty to installation by an accredited installer. If something fails in year two, a supply-and-install job leaves one party responsible rather than two blaming each other.
How much does it cost to switch from electric to gas hot water?
Changing energy type involves establishing a new gas point, decommissioning the electrical supply and often relocating the unit, which puts it in a materially higher bracket than a like-for-like swap. Published ranges put that conversion work in the order of $1,500 to $3,000 on top of the unit, depending on how far the gas has to run.
Do rebates reduce the price of solar or heat pump hot water?
Federal small-scale technology certificates apply to eligible solar and heat pump systems and are normally taken off the invoice by the installer rather than claimed by you afterwards. The value moves with the certificate market and the model, so ask for the price with and without it clearly itemised before you commit.