A quote you can compare shows five things: the unit, the labour, the tempering valve, removal of the old tank, and any rebate on its own line. Roll those into one figure and you can't tell a good price from a thin one.
Hot water usually gets replaced in a hurry. The tank goes on a Tuesday, someone's showering at a neighbour's place by Wednesday, and the first plumber who can come out gets the job. That's why quotes for this work are so often one line long.
The unit is not the job
The usual mix-up is between what a system costs to buy and what it costs to have working. A heat pump unit on its own runs $2,800–$5,200. Installed, the same type of system runs $3,000–$5,200. Electric storage shows the same gap.
Installer-reported ranges for Australia in 2026, before any state rebate. Each figure is sourced below.
Show these figures as a table
| Item | From | To |
|---|---|---|
| Heat pump, unit only | $2,800 | $5,200 |
| Heat pump, installed | $3,000 | $5,200 |
| Electric, unit only | $550 | $2,100 |
| Electric, installed | $800 | $2,500 |
When two quotes look far apart, this is often why. One's quoting the box. The other's quoting the box plus a licensed plumber, valves, fittings and a trip to the tip.
Labour: ask for the rate and the hours
Industry guides put plumber labour at $80–$120 per hour for this work, and a straightforward like-for-like swap at 2–4 hours. Multiply them for a sanity check, not a price. A tank in a roof space, a narrow side path or a switch from gas to electric all add hours, and going gas to electric often brings an electrician too, reported at $100–$400 where it's needed.
The tempering valve line
Heated water at bathroom fixtures can't be delivered hotter than 50 °C, so a tempering valve is part of the work, not an optional extra. Guides put it at $80–$150 as a line item. A quote that doesn't mention one is either assuming the existing valve is fine or hasn't looked. Ask which. How the rule works.
Removal and disposal
Someone has to take the old tank away, and a full one is heavy. Removal and disposal is reported at $80–$200. It's a small line, and the one most likely to cause an argument on the day if nobody wrote it down.
Where the rebate should appear
Federal small-scale technology certificates are already in your price. Your installer's quoted price already includes the federal STC discount, so there's nothing extra to take off for them. State programs differ. In NSW the Energy Savings Scheme comes to you as an upfront discount, so it should be visible as its own line rather than folded quietly into the total. In Victoria two separate reductions apply in a set order, which is worth seeing worked through.
If a quote shows a big discount but no scheme name, ask which program it comes from. The answer tells you whether it's a real incentive or just a sale price. Rebates by state lists what's actually open.
Four questions that sort out most quotes
- Is this price supply and install, or supply only?
- What brand, model and capacity, and is it on the approved list for the rebate you're claiming?
- Does it include a tempering valve, removal of the old unit, and any electrical work?
- Which rebate is in this price, and what is the figure before it comes off?
Prices here are ranges reported by industry guides, not fixed quotes. They're useful for spotting an outlier, not for predicting your own job.
If you're a plumber, these are the questions homeowners on this site are told to ask. Our websites for plumbers are built so customers find those answers before they call.