“What size do I need?” It’s the question we get most often – and it’s a good one to ask before you commit to a system. Get it right, and you’ll have reliable hot water every morning without paying for capacity you don’t need.
Get it wrong, and you’re either running cold by the second shower or overspending on a half-empty tank most of the year.
We’ve put this guide together based on what we see in Perth homes every week. We’ll walk you through the daily usage numbers, map our specific tank sizes to real household types, and give you four family scenarios so you can see exactly where you fit.
Key Takeaways
- As a rule of thumb, plan for around 50 litres of hot water per person per day – Perth households often run a little higher due to lifestyle and climate.
- We stock Reclaim Energy systems in 160L, 250L, 315L, and 400L, plus the Apricus at 260L – each suited to a different household profile.
- Heat pump systems recover efficiently throughout the day, particularly when paired with solar or off-peak tariffs.
- Teenagers, home offices, and frequent guests are the three most common reasons a household needs to size up.
- Undersizing is the bigger risk; a tank that runs cold by the third shower is far more disruptive than one that is slightly larger than needed.
How Much Hot Water Does Your Household Actually Use?
As a rule of thumb, plan for around 50 litres of hot water per person per day. That covers showers, hand washing, dishes, and laundry on a typical day. A household with two or three kids or one teenager often uses 150-170 litres daily; households with two teenagers who shower for 10 minutes or more can push well past 200 litres.
In Perth, usage tends to sit at the higher end of the range. The warmer climate means more rinsing off after being outdoors, sports, or gardening. Longer daylight hours stretch the active part of the day. And summer entertaining – extra guests, backyard use, outdoor showers, adds to weekend demand in ways that aren’t obvious from a weekday average.
Household Size | Typical Daily Use | Recommended Tank |
1-2 people | 50-100L per day | 160L |
2-3 people | 100-150L per day | 250L-260L |
3-4 people | 150-200L per day | 250L-315L |
4-5 people | 200-250L per day | 315L-400L |
5+ people | 250L+ per day | 400L |
One thing worth keeping in mind: daily totals matter less than peak demand. If four people shower within 90 minutes every morning, your tank needs to handle that burst comfortably. That’s why we look at household size and morning routines together, not just litres per day.
Our Sizing Chart: Reclaim and Apricus Options
Here’s how our specific systems map to different household types. We stock the Reclaim heat pump in four sizes and the Apricus hot water heat pump in one size. Each suits a different profile:
Tank Size | System | Best For | Notes |
160L | Reclaim Energy | 1-2 people | Couples, singles with occasional guests. Most compact footprint. |
250L | Reclaim Energy | 2-3 people | Small families or couples who use more water than average. |
260L | Apricus | 2-4 people | Good all-rounder. Compact integrated design, suits limited spaces. |
315L | Reclaim Energy | 3-4 people | The sweet spot for a family of four, especially with teenagers. |
400L | Reclaim Energy | 5+ people | Large households, frequent entertaining, or high-demand homes. |
The 250L and 260L options come up most often for Perth households replacing a standard electric storage system. The 315L Reclaim is our most popular size overall – it suits the typical 4-bedroom Perth home comfortably and gives a buffer for higher-demand days.
Four Perth Family Scenarios
Scenario 1: Young couple, no kids
Two adults, both working, one bathroom. Daily hot water demand sits around 80-100L. A 160L Reclaim is the right call here; it’s compact, efficient, and more than sufficient. If you work from home or have regular overnight guests, step up to the 250L.
Scenario 2: Family of four with primary school kids
Two adults and two younger children. Kids this age take shorter showers and use less hot water than teenagers. A 250L Reclaim or the 260L Apricus handles this household well. If you have two bathrooms running simultaneously in the morning rush, the 315L gives you a comfortable buffer.
Scenario 3: Family of four with teenagers
This is where we see the most undersizing. Teenagers shower longer – often well past the five minutes a younger child would take. Morning demand spikes hard. We’d recommend the 315L Reclaim as the baseline here. If you’ve got two teenagers both showering in the morning, the 400L is worth considering.
Scenario 4: Multi-generational or larger household
Five or more people under one roof – whether that’s grandparents, adult children, or a blended family. The 400L Reclaim is the right system. It’s also the one to consider if you run a home business, have a granny flat, or regularly host extended family on weekends.
What Happens If You Get the Size Wrong?
Undersizing
The system runs out of hot water before everyone has showered. The heat pump then works overtime to recover – running longer cycles and using more electricity. Over time, the extra wear increases servicing requirements. If this is already happening with your current system, it’s a sign it’s too small, not that heat pumps can’t keep up.
Oversizing
Less of a practical problem, but you’ll pay more upfront for capacity you don’t use. There’s a small amount of standby heat loss from maintaining a larger volume of water, though modern heat pumps minimise this with good tank insulation. Oversizing by one step – say, choosing a 315L when a 250L would do – isn’t a disaster. It’s a much smaller problem than undersizing.
If you’re genuinely unsure, call us before you commit. We’ll ask a few quick questions about your household and give you a straight answer, no pressure, just the right size for your home.
Frequently Asked Questions
Can I use the same size tank I had with my old electric system?
Usually, yes, with one caveat. If you were already running out of hot water with your old system, now’s the time to size up. If it was working fine, an equivalent heat pump capacity would perform at least as well. Heat pumps recover efficiently throughout the day, particularly when paired with solar panels or an off-peak tariff.
Does a heat pump need a bigger tank than a gas system?
Not necessarily. We generally recommend the same capacity you’d choose for a gas system unless you have specific peak demand concerns. In Perth’s climate, where ambient temperatures stay warm for most of the year, heat pump recovery is fast and consistent.
Does hot water use change with the seasons in Perth?
Slightly. Summer brings more frequent outdoor rinsing and extra guests. Winter sees longer, hotter showers. The good news is our systems, both the Reclaim and Apricus, operate at full efficiency in Perth’s climate year-round. Even in winter, with average minimums around 7.9 degrees, performance stays consistent.
What if our household size changes after installation?
Heat pumps are long-term systems – with proper servicing, they run for 10 to 15 years. If you’re expecting the household to grow in the next few years, it’s worth sizing up now rather than replacing early. It’s a conversation we’re happy to have before we book anything in.
