--- title: "Stiebel Eltron Hydronic Heat Pumps: The Range, Prices and Real-World Performance" date: 2026-09-06T13:00:00+10:00 author: Darren Burch canonical_url: "https://sogeo.com.au/blog/stiebel-eltron-hydronic-heat-pumps-range-prices-performance" section: Pages --- ![Geothermal Plant Room]() # Stiebel Eltron Hydronic Heat Pumps: The Range, Prices and Real-World Performance SóGeo installs the full Stiebel Eltron WPL-A air source range and is the exclusive Victorian distributor and installer of the WPE geothermal range. Here is the range, what a system costs installed in Melbourne, and the efficiency our systems measure in the field. **Short version first.** SóGeo installs the full Stiebel Eltron WPL-A air source hydronic range across Melbourne, and we are the exclusive Victorian distributor and installer of the Stiebel Eltron WPE geothermal range. This guide covers the models, what a system costs installed, the efficiency the units are rated at versus what our installs actually measure, and how to decide between air source and geothermal. It is written by the people who design, supply, install and commission these systems, not by a retailer reading a datasheet. ## The Stiebel Eltron hydronic range we install Stiebel Eltron is a German manufacturer with a long reputation for inverter hydronic heat pumps. A hydronic heat pump heats water rather than air, then circulates that water through underfloor pipework, radiators or fan coils, and reverses in summer to cool the home through the same pipes. Two Stiebel families cover almost every Melbourne home: the WPL-A Trend for air source, and the WPE range for geothermal. The [hydronic heat pumps page](/hydronic-heat-pumps) has the supply and install detail; this guide goes deeper on choosing and pricing. ### Stiebel Eltron WPL-A Trend, air source The WPL-A Trend is the unit on most of our residential installs. One outdoor unit handles heating, summer cooling and hot water, and it runs on R290, a natural refrigerant with very low environmental impact. Three models cover most homes: Model Rated output COP Sound level WPL-A Trend 10.2 4.26 kW 5.40 63 dB(A) WPL-A Trend 13.2 5.56 kW 5.36 66 dB(A) WPL-A Trend 17.2 7.96 kW 5.29 67 dB(A) Output and COP are rated at A7/W35, the standard 7°C air and 35°C flow test point. The model number reflects the size class; the rated figures are the standard part-load test point, and the inverter modulates well above them when the home calls for it. We size every unit against a room by room heat-loss calculation, never against the badge. - A+++ energy efficiency class across all three models - Inverter compressor that modulates output to the load instead of cycling on and off - Flow temperatures up to 75°C, high enough to drive existing radiators in a retrofit, which most heat pumps cannot manage - Smart Grid ready for connection to solar and home energy management - Made in Germany ### Stiebel Eltron WPE, geothermal For ground source systems we install the Stiebel Eltron WPE range, and we are the exclusive Victorian distributor and installer of it. A geothermal unit draws its heat from a buried ground loop instead of the air, so it holds a COP of 5 to 7 year-round, because ground temperatures stay stable while the air does not. The buried pipework lasts 50 or more years. The inverter WPE-I series spans roughly 33 to 87 kW of nominal output, and units cascade for larger homes and commercial buildings. The same unit makes the domestic hot water through a diverting valve, and in summer its de-superheater turns the heat pulled out of the house during cooling into free hot water, or into pool and spa heating, which on a heated pool is typically worth $2,000 to $6,000 a year. The full picture is on our [ground source heat pumps page](/ground-source-heat-pumps). ## What a Stiebel Eltron hydronic heat pump costs installed For homeowners we price the installed system rather than a boxed unit, because the design and commissioning are what deliver the efficiency, and a unit sold by one business and installed by another is where most underperforming systems come from. A straightforward gas boiler to heat pump swap that keeps your existing radiators starts at $15,000 with SóGeo. Most projects run higher with home size, scope, hot water integration, and any radiator or insulation upgrades the heat-loss calculation identifies. Adding a stainless steel hot water cylinder so the heat pump takes over domestic hot water typically adds $4,000 to $5,000. Larger homes and new builds are quoted from drawings after a site visit, with a fixed quote against the design. Geothermal costs more upfront than air source because of the ground loop and the trenching or drilling that goes with it. Our clients often see payback in 5 to 10 years through 50 to 70% lower running costs. On running costs generally, a typical Melbourne home spends around $900 to $1,350 a year on electricity with a hydronic heat pump system, against around $4,100 a year running the same hydronic system on a gas boiler at current tariffs. One thing we will tell you straight: there is currently no Victorian rebate for hydronic space-heating heat pump systems. The well-known programs cover hot water heat pumps as a separate measure. Our [cost guide](/blog/how-much-does-it-cost-to-switch-from-gas-to-hydronic-heat-pumps) has the full breakdown. 01 ![Pump room 3]() ### How efficient are they really? Rated COP versus measured SCOP The datasheet number and the bill number are different things, and only one of them is under the installer’s control. The 5.40 COP on the WPL-A Trend is measured at the A7/W35 test point, a mild 7°C day feeding 35°C water. It is a real figure, and the right way to compare units on a level playing field, but it is not what shows up on your bill. That is the SCOP, the seasonal average across a whole Melbourne winter. A SóGeo install typically delivers a SCOP of 5 or higher across the year, and never less than 4 even on a demanding retrofit, because our heat-loss calculation upsizes radiators where needed to keep flow temperatures down. The market average for air source installs sits at SCOP 3.0 to 3.5, which we treat as a poor result. Geothermal goes further because the ground stays warm when the air does not. The SCOPs measured on our own projects are 8.1 at Coimadai, 7.4 at Invermay, 5.2 at Port Campbell and 5.1 on the Main Ridge lake loop, and Port Campbell cut the home’s power consumption by 70% on a single-phase supply. The [case studies](/case-studies) have the detail. What separates those numbers from the industry average is design discipline: correct sizing against the heat-loss calculation, weather-compensation tuning, and proper hydraulic balancing so the return water is genuinely cool. 01 ![Stiebel eltron wpl a hydronic heat pump melbourne]() ### Air source or geothermal: which Stiebel suits your home? Both ranges deliver the same comfort through the same pipes. The site, the budget and the electrical supply decide. Air source, the WPL-A Trend, is the right answer for most Melbourne homes: lower upfront cost, no ground works, and a SCOP of 5 or higher when it is designed properly. It suits boiler swaps, renovations and new builds where the ground is not available or the budget favours a faster payback. Geothermal, the WPE range, earns its premium on larger homes, rural and coastal properties, homes with a pool, and projects where the electrical supply is tight. A geothermal system holds its COP through the coldest morning and the hottest afternoon, recovers summer cooling heat into hot water and pools, and at winter design conditions air source draws roughly 40% more power for the same heat, which is often the difference between fitting the existing switchboard and paying for a supply upgrade. Our guide to [maximum demand and heat pumps](/blog/geothermal-heat-pumps-in-melbourne-sydney-reduce-connected-load-and-save-on-electrical-upgrades) works through the numbers. ## Why the EHPA quality label matters The European Heat Pump Association (EHPA) runs the quality label scheme that the European heat pump industry measures itself against. To carry the label, a heat pump’s performance is tested in an independent laboratory rather than declared by the manufacturer, and the brand has to back the product with a service and warranty network in the country it sells into. The Stiebel Eltron ranges we install are tested under this scheme. That matters in Australia because the market is filling with imported units whose datasheet figures nobody has verified, and because a heat pump is a twenty-year purchase that needs parts and support long after the sale. A label is not a substitute for a good design, but it is the floor we will not go below. *SóGeo designs, supplies and installs Stiebel Eltron hydronic heat pump systems across Melbourne, and is the exclusive Victorian distributor and installer of the WPE geothermal range. The next step is a site visit and a room by room heat-loss calculation, then a fixed quote against the design.* [*Talk to SóGeo about a Stiebel Eltron system*](/contact-us)*.* ## Common questions about Stiebel Eltron hydronic heat pumps ### How much does a Stiebel Eltron hydronic heat pump cost? ➕ Installed, a gas boiler to heat pump swap that keeps your radiators starts at $15,000 with SóGeo, and larger or new-build systems are quoted from drawings. Adding a hot water cylinder typically adds $4,000 to $5,000. Geothermal systems cost more upfront for the ground loop, with payback often in 5 to 10 years. There is currently no Victorian rebate for the hydronic system itself; hot water heat pump programs are a separate measure, covered in our [rebates guide](/blog/victoria-heat-pump-and-hot-water-rebates-2026-guide). ### Are Stiebel Eltron heat pumps any good? ➕ The units are A+++ rated, inverter driven and made in Germany, and the air source range reaches a COP of 5.40 at the standard test point. The better answer is what installed systems measure: a SóGeo install typically returns a SCOP of 5 or higher, and our geothermal projects have measured between 5.1 and 8.1. The unit is only half of that result. The other half is a heat-loss calculation, correct sizing and proper commissioning, which is why we supply and install as one job. ### Can a Stiebel heat pump run my existing radiators? ➕ Often, yes. The WPL-A Trend reaches flow temperatures of 75°C, high enough to drive existing radiators that older heat pumps could not. Most Melbourne radiator systems were also sized by rule of thumb rather than a heat-loss calculation, which left them oversized, and an oversized radiator is exactly what a heat pump wants, because it can deliver full warmth at lower water temperatures. Where a room needs more surface area, we swap a single panel for a double or triple panel of the same length in the same position, so your pipework stays untouched. Our [boiler guide](/blog/hydronic-heating-boilers-repair-replace-or-switch) covers the swap in detail. ### Do Stiebel Eltron heat pumps have problems? ➕ Most heat pump problems we are called to look at are design and commissioning problems, not equipment problems: an undersized unit running flat out, an oversized one short cycling, or a system nobody balanced. The unit gets the blame for a decision made before it was unboxed. That is the case for one team owning design, supply, installation and commissioning, and it is how we work. We also service what we install, from our base in Carrum Downs in Melbourne’s south east. ### What about warranty and service? ➕ Every unit is backed by the Stiebel Eltron Australia manufacturer warranty, and SóGeo services and supports the systems it installs. Ask us for the current warranty terms for the model in your design. ### Which is more efficient, the WPL air source or the WPE geothermal? ➕ Geothermal. The WPE holds a COP of 5 to 7 all year because the ground loop temperature is stable, while air source efficiency dips on the coldest mornings and the hottest afternoons. For most Melbourne homes the air source unit’s SCOP of 5 or higher is already excellent value; geothermal makes sense when the site, the load or the electrical supply justify the ground loop. ## Our Partners [ ![Reece](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Reece.png) ](https://www.reece.com.au/) [ ![Stiebel Eltron](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Stiebel-Eltron.png) ](https://www.stiebel-eltron.com.au/) [ ![Mitsubishi](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Mitsubishi.png) ](https://www.mitsubishielectric.com.au/) [ ![Purmo](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/Purmo.png) ](https://www.purmo.com/au) [ ![Viessmann](https://sogeo.com.au/uploads/suppliers/_AUTOx96_crop_center-center_none_ns/viessmann_wordmark_rgb_1_vitorange.png) ](https://www.viessmann.com.au/)