Education Guide — Hot Water Heat Pumps
Education Guide — Hot Water Heat Pumps
When we assess any hot water system, we look at two things: how much hot water is stored in the tank, and how fast the system can reheat it once people start using it. Getting these numbers right for your situation is the difference between a system that handles peak demand and one that leaves someone with a cold shower.
The Two Numbers That Matter
One stores hot water. The other refills it. You need the right balance of both.
①
This is how much hot water is stored and ready to use at any one time. A larger tank means more hot water available before the system needs to recover — critical when multiple people use it in quick succession.
②
This is how fast the system can reheat cold water back to temperature. A high recovery rate means the system can keep up during back-to-back demand. This number is often overlooked — and it's the one that matters most under pressure.
System Comparison
All tanks in our catalogue are approved for rebate activities under the VEU scheme. Recovery rates represent typical warm-weather operating conditions.
| System | Tank | Recovery Rate | Cold Weather Impact | Best For |
|---|---|---|---|---|
| Gas (Aquamax) | Smaller | 200–250 L/hr | ✅ Consistent in all conditions | High back-to-back demand, motels, large households |
|
Standard Heat Pump (270L) Aqua Plus 270L · iStore 270L · Aquatech |
270L | 60–90 L/hr | ⚠️ Slower in cold & overnight | Most Victorian households (4–5 people), spread-out usage |
| 400L Reclaim CO₂ BEST | 400L | 120–160 L/hr | ⚠️ Some reduction, less than standard | Higher-demand homes, small commercial, motels |
Recovery Rate at a Glance
Recovery rate (litres per hour) is the number that determines whether your system can keep up during peak usage. Gas leads significantly, with the Reclaim CO₂ offering a meaningful improvement over the standard 270L unit.
⚠️ Heat pump recovery rates shown represent warm-weather performance. In cold or winter conditions, recovery rates drop further. Gas systems are not affected by outdoor temperature.
🌡️
Heat pumps pull heat from the surrounding air to heat your water — so when the weather is warm, they perform well and recover faster.
When it's cold — especially overnight or in winter — their recovery rate drops and it can take significantly longer to reheat the tank than the figures above suggest.
Gas systems don't have this issue. They deliver consistent performance regardless of the temperature outside — worth keeping in mind if you have high demand early in the morning or live in a cooler part of Victoria.
Why Context Matters
The same system that works perfectly for a Victorian family home can fall short in a higher-demand environment.
In a typical 4–5 person home, a standard heat pump works well because usage is spread out. There's usually enough time between showers for the system to recover — so slower reheat rates are rarely a problem day-to-day.
Where multiple people use hot water back-to-back, recovery rate becomes critical. If the system can't keep up, you don't just run out of hot water — you end up with unhappy guests.
Real-world example: A standard 270L heat pump running at 60–90 L/hr can take 3–4 hours to fully recover after heavy use. In a motel with 6–8 guests showering at check-out time, the tank will empty faster than it refills — leaving later guests with lukewarm or cold water. The 400L Reclaim CO₂, with its larger tank and 120–160 L/hr recovery rate, is far better suited to handle this kind of consecutive demand.
Three things to keep in mind when sizing your hot water system
A bigger tank helps, but if recovery rate is too slow, it will empty faster than it refills during peak usage — like back-to-back morning showers.
Heat pumps pull heat from the air. Cold overnight or winter conditions reduce recovery rates further — a risk gas systems simply don't carry.
The 400L Reclaim CO₂ offers the best balance for higher-demand settings. Gas remains the fastest and most consistent option regardless of conditions.
Every install is different. Our team of plumbers, electricians and refrigeration specialists will assess your hot water usage, location and existing setup to recommend the right system — with all available Victorian rebates applied.
MORNINGTON
2/13 Elite Way,
Mornington 3931
ALTONA NORTH
28/40-52 McArthurs Road,
Altona North 3025