Rinnai vs Emerald: Which Heat Pump Is Better? (2026)
Quick Verdict
Emerald is the more efficient choice with a higher COP rating, meaning lower running costs over time.
Side-by-Side Comparison
| Feature | Rinnai | Emerald |
|---|---|---|
| Price range (installed) | $3,350 - $6,000 | $2,750 - $3,750Lower |
| COP (efficiency) | 3.9 | 5.2Higher |
| Tank warranty | 7 years | 7 years |
| Compressor warranty | 5 years | 5 years |
| Noise level | 45dBQuieter | 49dB |
| Annual running cost | ~$304/yr | ~$228/yrLower |
| Refrigerant type | R134a | R134a |
| Country of manufacture | Japan/Australia | Australia |
| Australian made | No | No |
| Best for | Homeowners wanting a trusted household name with the best installer availability and an Australian-made option | Households wanting a high published efficiency and a long tank warranty without paying split-system prices |
Price Comparison
Rinnai starts from $3,350 installed (before rebates), while Emerald starts from $2,750. That is a difference of roughly $600 at the entry level. Emerald 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 Emerald reaches 5.2. The Emerald is 33% more efficient, which translates to roughly $76 less per year in running costs. Over a 10-year lifespan, that efficiency advantage adds up to approximately $760 in savings.
Warranty Comparison
Rinnai offers a 7-year tank warranty and 5-year compressor warranty. Emerald offers a 7-year tank warranty and 5-year compressor warranty. Both brands offer the same tank warranty length, so warranty coverage is comparable.
Noise Comparison
Noise is an important consideration, especially for suburban installations where the unit may be close to bedrooms or neighbouring properties. Rinnai publishes 45dB for its quietest model, and Emerald publishes 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 Emerald 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 Australia
- 340L is largest integrated residential heat pump in Australia
- 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
Emerald
Pros
- Among the cheapest R290 units with a published COP above 4.8
- Pro series carries a 7-year tank warranty, 8 if you register it
- Two magnesium anodes on the Pro tank
- Widely stocked, so quotes are easy to compare
- Runs on the heat pump alone down to -7C
Cons
- Manufacturing location is not published
- Not on the Solar Victoria locally made list, so it earns the lower Victorian rebate tier
- The Select series drops to a 5-year tank and 2-year labour warranty
- Emerald quotes 39 to 40 dB from 3 metres on its web pages while the data sheets show 49 to 50 dB at 1 metre, so compare it with other brands at 1 metre
Which Should You Choose?
Choose Rinnai if...
- Quiet operation matters to you (45dB vs 49dB)
- You're in Victoria (models on Solar Victoria's locally made list = higher rebate tier of $1,400 vs $1,000)
Choose Emerald if...
- You want a lower upfront cost (from $2,750 vs $3,350)
- You want the best efficiency and lowest running costs (COP 5.2 vs 3.9)
- You want lower annual running costs (~$228/yr vs ~$304/yr)
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 has models on Solar Victoria's locally made list, which qualify for the higher $1,400 tier.
Heat pump guides
- Every Australian heat pump rebate, with the dated changes
- The best heat pump hot water brands in Australia
- Heat pump hot water cost in Australia
- Victoria heat pump rebates
- New South Wales heat pump rebates
- Queensland heat pump rebates
- South Australia heat pump rebates
- Australian Capital Territory heat pump rebates
- Western Australia heat pump rebates
- Tasmania heat pump rebates
- Northern Territory heat pump rebates
What are you replacing?
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