Stiebel Eltron vs Dux: Which Heat Pump Is Better? (2026)
Quick Verdict
Dux is the more efficient choice with a higher COP rating, meaning lower running costs over time.
Side-by-Side Comparison
| Feature | Stiebel Eltron | Dux |
|---|---|---|
| Price range (installed) | $3,500 - $5,000 | $3,300 - $3,850Lower |
| COP (efficiency) | 3.8 | 4.7Higher |
| Tank warranty | 5 years | 7 yearsLonger |
| Compressor warranty | 5 yearsLonger | 3 years |
| Noise level | 44dB | Not published |
| Annual running cost | ~$312/yr | ~$252/yrLower |
| Refrigerant type | R134a | R134a |
| Country of manufacture | Germany | Australia |
| Australian made | No | Yes |
| Best for | Those who value German engineering and build quality at a mid-to-premium price point | Victorian households chasing the higher locally made rebate tier, and anyone who wants an Australian-built tank |
Price Comparison
Stiebel Eltron starts from $3,500 installed (before rebates), while Dux starts from $3,300. That is a difference of roughly $200 at the entry level. Dux is the more budget-friendly option upfront, though Stiebel Eltron 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. Stiebel Eltron achieves a COP of 3.8, while Dux reaches 4.7. The Dux is 24% more efficient, which translates to roughly $60 less per year in running costs. Over a 10-year lifespan, that efficiency advantage adds up to approximately $600 in savings.
Warranty Comparison
Stiebel Eltron offers a 5-year tank warranty and 5-year compressor warranty. Dux offers a 7-year tank warranty and 3-year compressor warranty. The Dux has the stronger warranty coverage with 7 years on the tank, giving you 2 extra years of protection compared to the Stiebel Eltron. 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. Stiebel Eltron publishes 44dB for its quietest model, and Dux publishes none either. Makers measure sound level at different distances, and one of these two does not publish a figure at all, so ask the installer for the model's data sheet before you compare them on noise.
Climate Suitability
The type of refrigerant a heat pump uses significantly affects its performance in cold weather. Stiebel Eltron uses R134a refrigerant, while Dux 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
Stiebel Eltron
Pros
- German engineering quality
- Good efficiency
- Solid warranty backing
- Established global brand (100+ years)
- Strong Australian support network
Cons
- Higher cost than local brands
- Heavier unit
- Not Australian-made (misses higher VIC rebate tier)
Dux
Pros
- The Ecosmart DHC range is designed and manufactured in Australia
- On the Solar Victoria locally made list, so it earns the higher Victorian rebate tier
- 7-year tank warranty
- Y-class commercial enamel tank with dual anodes
- Published COP of 4.63 on the 285L
Cons
- Dux publishes no sound level for any Ecosmart model, so you cannot compare it on noise
- Only 3 years on the heat pump components, and 1 year on everything else
- The Pro-Series makes no Australian-made claim and is not on the locally made list
- The model sold as 300DHC25 holds 285L, not 300L
- No minimum operating temperature published for the DHC range
Which Should You Choose?
Choose Stiebel Eltron if...
- Those who value German engineering and build quality at a mid-to-premium price point
Choose Dux if...
- You want a lower upfront cost (from $3,300 vs $3,500)
- You want the best efficiency and lowest running costs (COP 4.7 vs 3.8)
- You want a longer tank warranty (7 years vs 5 years)
- You want lower annual running costs (~$252/yr vs ~$312/yr)
- You're in Victoria (models on Solar Victoria's locally made list = higher rebate tier of $1,400 vs $1,000)
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. Dux 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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