John Nighingale — Professional Plumber at Plumb It Right
Solar Hot Water in Perth: Is It Worth It and What Rebates Are Available?
Key Takeaways
- •Solar hot water suits Perth homes with an unshaded roof and steady daily hot water use.
- •A heat pump is the better pick for most homes, because it needs no roof collectors and pairs with rooftop solar panels.
- •Rebate amounts and eligibility change, so get the current rules confirmed in writing before you sign a quote.
- •Gas boosters and gas hot water repairs must be done by a licensed gas fitter in WA.
- •A fixed quote after a site visit beats any online price estimate.
You are staring at a hot water system quote and every salesperson says something different about solar. Some promise the system pays for itself, others say the rebates have dried up. This guide gives you a straight answer on when solar hot water earns its price in Perth, and how to check what you can claim.
What Is Solar Hot Water, and What Gets It Confused With Other Systems?
Roof collectors heat your water directly, which is a different job to solar panels.
A solar hot water system uses roof-mounted collectors to heat water, which is stored in a tank. A booster (electric or gas) tops the water up when the sun is not enough. Our page on solar hot water systems covers the hardware.
People confuse it with two other things. Solar PV panels make electricity for the whole house. A heat pump is an electric unit that heats water without roof collectors, and it can run off PV power. If you want the full side-by-side, the hub article Perth Hot Water Systems Explained: Heat Pump, Solar, Gas or Electric? walks through all four types on our hot water systems page.
What Rebates Are Available for Solar Hot Water in Perth?
Rebate rules change, so verify them before you pay a deposit.
I am not going to print a dollar figure here. Rebate amounts and eligibility change, and a number in a blog post goes out of date faster than the quote in your hand. What I can give you is the list of questions that protects your money.
- •Is this exact model eligible for any current rebate or incentive?
- •Does the incentive apply to a replacement, a new build, or both?
- •Is it taken off the quote upfront, or do you claim it afterwards?
- •Does your installer need specific licences to make the claim valid?
Ask for the answers in writing on the quote. If a seller will not put the rebate in writing, treat the discount as unconfirmed.
Which Hot Water System Is Worth It for a Perth Home?
A ranked shortlist, scored on the criteria in the next section.
I install heat pumps and solar hot water, so you should know where my bias sits. I rank on cost, running cost and site needs, and I say plainly where my own top pick loses.
1. Heat pump, best for homes with rooftop solar panels
A heat pump needs no roof collectors and fits where a solar thermal roof array will not. It runs on electricity, so it pairs well with PV panels. One customer on our Google profile (4.9 from 52 reviews) wrote that the iStore 270L heat pump we installed "integrates well with the Solar/Battery" and the price was competitive.
The drawback is that it still draws electricity every day, so a sunny unshaded roof with solar thermal can beat it on running cost. Our heat pump page has the detail, and How Much Does a Heat Pump Hot Water System Cost to Run in Perth? covers the numbers.
Best suited for: Households that already have rooftop solar panels or plan to add them. It is also the pick when the roof is shaded or has no space for collectors.
2. Solar hot water, best for unshaded roofs and heavy daily use
Perth gets plenty of sun, and a roof that faces it well lets the collectors do most of the heating. A booster covers cloudy stretches. If the booster is gas, a licensed gas fitter must connect and service it, since DIY gas work is illegal in WA.
The honest drawbacks are a high upfront price and the roof requirement. A shaded or poorly angled roof wastes the investment, and I will tell you that on the site visit rather than sell you a system.
Best suited for: Larger households with steady daily hot water use and a clear, sun-facing roof. It is a poor fit for shaded roofs or short-term owners.
3. Gas instantaneous, best for compact homes with mains gas
An instantaneous unit heats water as you use it, so there is no tank to keep hot and no running out mid-shower. It takes little wall space. Installation and repair sit with a licensed gas fitter, which we are.
Best suited for: Homes with mains gas and limited space for a tank. It does not help you use your own solar power, so it is weaker for homes with PV panels.
4. Gas storage, best for a straight swap on an existing gas system
Gas storage keeps a tank of heated water ready, which handles several taps at once. It is the easiest like-for-like replacement when your home is already plumbed for gas. We compare it with instantaneous in Gas Storage vs Gas Instantaneous Hot Water: Which Is Right for Your Perth Home?.
Best suited for: Homes replacing an existing gas storage unit with the least change to pipework. It ranks fourth because it offers no solar benefit.
5. Electric storage, best for the lowest upfront cost
Electric storage is the cheapest to buy and the simplest to install. It costs the most to run, and running it dry can burn out the element. A corroded, leaking tank means replacement, not repair.
If your unit is failing, Signs Your Hot Water System Needs Replacing and What to Do Next helps you decide. Electric Storage Hot Water Systems: Pros, Cons and When They Still Make Sense covers the cases where it still wins.
Best suited for: Tight budgets, rentals, or low-use households where a cheap replacement matters most. Expect higher power bills than the options above.
How Did We Rank These Hot Water Systems?
Each position is earned on the criteria below, not by what we install most often. Where a rival wins a criterion, the table shows it.
Upfront cost
Relative purchase and installation cost across the five types. It decides how long any saving takes to repay.
Running cost
Relative daily energy use, from gas or electricity. This is where solar and heat pump systems earn their price.
Site needs
Roof, wall or gas connection a home must have. A system that cannot be installed well saves nothing.
Solar PV compatibility
Whether the system can use power from rooftop panels. It matters for homes that already export solar.
Side-by-Side Comparison
| Option | Best for | Upfront cost | Running cost | Site needs | Uses solar PV power |
|---|---|---|---|---|---|
| 1. Heat pump | Households with rooftop solar panels or a shaded roof | High | Low | Outdoor space for the unit | Yes |
| 2. Solar hot water | Larger households with an unshaded, sun-facing roof | Highest | Low | Suitable roof space | Not directly |
| 3. Gas instantaneous | Homes with mains gas and limited tank space | Medium | Medium | Mains gas, wall space | No |
| 4. Gas storage | Homes replacing an existing gas storage unit | Medium | Medium | Mains gas, tank space | No |
| 5. Electric storage | Tight budgets, rentals, low-use households | Lowest | Highest | Tank space | Only with a timer or controller |
Which Hot Water System Fits Your Situation?
Match your home to the row that sounds most like you.
| If you are… | Look for | Best fit |
|---|---|---|
| You have rooftop solar panels and a battery or export | A system that can run on your own PV power | Heat pump |
| You have a large family and a sun-facing, unshaded roof | Roof space and high daily hot water use | Solar hot water |
| You have mains gas and no space for a tank | Compact unit with continuous supply | Gas instantaneous |
| Your gas storage unit has failed and you want the simplest swap | Like-for-like connection to existing gas pipework | Gas storage |
| You need the cheapest replacement today | Lowest purchase and installation cost | Electric storage |
Solar Hot Water Questions Perth Homeowners Ask
Short answers to the questions that come up on every quote.
Is solar hot water worth it in Perth?
Yes, if your roof faces the sun without shade and your household uses hot water daily. If your roof is shaded or you already have PV panels, a heat pump is usually the better buy.
How do I find out which rebates I qualify for?
Ask your installer to confirm in writing which incentives apply to the exact model and your property. Rules change, so check the current requirements before you pay a deposit.
Does a solar hot water system need a gas fitter?
Only if the booster is gas. Gas work must be done by a licensed gas fitter in WA, and DIY gas work is illegal.
Should I repair or replace my old system before choosing solar?
A leaking tank cannot be repaired, so replace it and use the moment to choose a better system type. A newer unit with a single failed component is usually worth repairing first.
Want a Fixed Quote on Your Next Hot Water System?
Call or text John on 0408 012 993 and get a fixed price with no callout fee. Ask him to check which incentives apply to your home.
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Part of our guide: Perth Hot Water Systems Explained: Heat Pump, Solar, Gas or Electric?
John Nighingale
Professional Plumber · Plumb It Right
John Nightingale has 38+ years’ experience of working in the plumbing industry in Perth Western Australia and previously in the United Kingdom.
