Rinnai vs iStore: Which Heat Pump Is Better? (2026)
Quick Verdict
Rinnai is the more efficient choice with a higher COP rating, meaning lower running costs over time, while iStore is more budget-friendly with a lower upfront cost starting from $2,800.
Side-by-Side Comparison
| Feature | Rinnai | iStore |
|---|---|---|
| Price range (installed) | $3,350 - $4,800 | $2,800 - $4,200Lower |
| COP (efficiency) | 3.9Higher | 3.2 |
| Tank warranty | 7 yearsLonger | 5 years |
| Compressor warranty | 5 years | 5 years |
| Noise level | 45dBQuieter | 49dB |
| Annual running cost | ~$300/yrLower | ~$340/yr |
| Refrigerant type | R134a | R134a |
| Country of manufacture | Japan/Australia | Australia |
| Australian made | Yes | Yes |
| Best for | Homeowners wanting a trusted household name with the best installer availability and AU-made option | Budget-conscious households wanting maximum rebate impact and simple installation |
Price Comparison
Rinnai starts from $3,350 installed (before rebates), while iStore starts from $2,800. That is a difference of roughly $550 at the entry level. iStore is the more budget-friendly option upfront, though Rinnai may deliver savings through lower running costs over time. Both prices are for fully installed systems before government rebates and STCs, which can reduce the out-of-pocket cost by $1,000 to $3,000 depending on your state.
Efficiency Comparison
COP (Coefficient of Performance) is the key efficiency metric for heat pumps. A higher COP means more heat output per unit of electricity consumed. Rinnai achieves a COP of 3.9, while iStore reaches 3.2. The Rinnai is 22% more efficient, which translates to roughly $40 less per year in running costs. Over a 10-year lifespan, that efficiency advantage adds up to approximately $400 in savings.
Warranty Comparison
Rinnai offers a 7-year tank warranty and 5-year compressor warranty. iStore offers a 5-year tank warranty and 5-year compressor warranty. The Rinnai has the stronger warranty coverage with 7 years on the tank, giving you 2 extra years of protection compared to the iStore. A longer tank warranty can provide significant peace of mind, as the tank is the most expensive component to replace.
Noise Comparison
Noise is an important consideration, especially for suburban installations where the unit may be close to bedrooms or neighbouring properties. Rinnai operates at 45dB, while iStore runs at 49dB. The Rinnai is quieter at 45dB. At this level, it is similar to a quiet office and should be unnoticeable from inside most homes.
Climate Suitability
The type of refrigerant a heat pump uses significantly affects its performance in cold weather. Rinnai uses R134a refrigerant, while iStore uses R134a. Both units use the same refrigerant type, so cold-weather performance should be comparable. R134a performs well in moderate climates but may lose some efficiency in very cold conditions.
Pros and Cons
Rinnai
Pros
- Australia's most trusted hot water brand
- AR Series is Australian-made (higher VIC rebate)
- Widest installer network in AU
- 340L is largest integrated residential heat pump in AU
- Smooth transition path from Rinnai gas
Cons
- Not the most efficient COP vs CO2 brands
- Only AR Series is Australian-made
- E-Series has shorter warranty
- Standard R134a refrigerant
iStore
Pros
- Most affordable option
- Australian company
- Simple installation
- Good rebate value (low cost means rebates cover more)
- Widely available
Cons
- Lower COP than premium brands
- Shorter warranty
- Noisier than split systems
- Higher running costs long-term
Which Should You Choose?
Choose Rinnai if...
- You want the best efficiency and lowest running costs (COP 3.9 vs 3.2)
- You want a longer tank warranty (7 years vs 5 years)
- Quiet operation matters to you (45dB vs 49dB)
- You want lower annual running costs (~$300/yr vs ~$340/yr)
Choose iStore if...
- You want a lower upfront cost (from $2,800 vs $3,350)
Buying in Victoria? Stack up to $2,700 in rebates
Whichever brand you pick, Victorian households can stack the Solar Victoria Hot Water Rebate ($1,000-$1,400), the Victorian Energy Upgrades discount ($500-$2,000), and federal STCs ($500-$1,200) ahead of the 1 March 2027 gas ban deadline. Rinnai is Australian-made and qualifies for the higher $1,400 Solar Victoria tier.
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