Boiler design

Optional heating coil integration X
Available with zero, one or two heating coils to integrate various heating sources
Hooked strip X
Hooked strip to simply and quickly fit the insulation
Different capacities X
Capacity of 500 to 5000 litres (special sizes available)
Fleece insulation X
Up to 38 per cent less storage loss as compared to soft foam insulation thanks to the energy-saving and environmentally friendly 100 mm fleece insulation.
Cogent to the smallest detail
- Up to 38 per cent less storage loss as compared to soft foam insulation thanks to the energy-saving and environmentally friendly 100 mm fleece insulation.
- Available with zero, one or two heating coils to integrate various heating sources.
- Hooked strip to simply and quickly fit the insulation.
- Capacity of 500 to 5000 litres (special sizes available)
The advantages at a glance
+ Rapid heating thanks to large smooth-tube indirect coil heaters
+ Optimum heat storage thanks to 100 mm ECO SKIN fleece insulation
+ The right accumulator solution for every situation

Greater efficiency for heat storage
The AccuWIN has large smooth-tube indirect coil heaters so heats up very fast. Thanks to its energy-saving 100 mm ECO SKIN fleece insulation, the AccuWIN has up to 38% less accumulator losses than comparable products with soft foam insulation. Should your boiler not be available, you can also heat up the content of your AccuWIN with an optional electric immersion heater.
Technical data
The Windhager AccuWIN Klassik heat accumulator is available with zero (eight versions), one (seven versions) or two (four versions) heating coils.
AccuWIN Klassik: 0 heating coils
Type | ACK 500 | ACK 800 | ACK 1000 | ACK 1500 | ACK 2000 | ACK 3000 | ACK 4000 | ACK 5000 | |
Contents | approx. l | 500 | 800 | 1,000 | 1,500 | 2,000 | 3,000 | 4,000 | 5,000 |
Coil heater surface top/bottom | m2 | –/– | –/– | –/– | –/– | –/– | –/– | –/– | –/– |
Coil heater content top/bottom | l | –/– | –/– | –/– | –/– | –/– | –/– | –/– | –/– |
Ø not including insulation | mm | 650 | 790 | 790 | 1000 | 1100 | 1250 | 1400 | 1600 |
Height not including insulation | mm | 1640 | 1700 | 2050 | 2150 | 2380 | 2596 | 2669 | 2770 |
Height including insulation | mm | 1725 | 1785 | 2135 | 2235 | 2465 | 2681 | 2754 | 2855 |
Tilted height not including insulation | mm | 1670 | 1750 | 2090 | 2270 | 2460 | 2650 | 2740 | 2893 |
Weight not including insulation | kg | 75 | 91 | 101 | 190 | 238 | 365 | 490 | 580 |
Supply and return connections | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 2" int. thread | 2" int. thread | 2" int. thread | |
Max. operating pressure | bar | 3 | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
Energy efficiency class | C | C | C | C | C | C | C | C |
AccuWIN Klassik: 1 heating coils
Type | ACK 501R | ACK 801R | ACK 1001R | ACK 1501R | ACK 2001R | ACK 3001R | ACK 5001R | |
Contents | approx. l | 500 | 800 | 1,000 | 1,500 | 2,000 | 3,000 | 5,000 |
Coil heater surface top/bottom | m2 | 1.8/– | 2.4/– | 3.0/– | 3.6/– | 4.2/– | 4.5/– | 6.0/– |
Coil heater content top/bottom | l | 11/– | 15/– | 19/– | 22/– | 26/– | 29/– | 39/– |
ø not including insulation | mm | 650 | 790 | 790 | 1000 | 1100 | 1250 | 1600 |
Height not including insulation | mm | 1640 | 1700 | 2050 | 2150 | 2380 | 2596 | 2770 |
Height including insulation | mm | 1725 | 1785 | 2135 | 2235 | 2465 | 2681 | 2855 |
Tilted height not including insulation | mm | 1670 | 1750 | 2090 | 2270 | 2460 | 2650 | 2893 |
Weight not including insulation | kg | 98 | 122 | 143 | 244 | 298 | 446 | 660 |
Supply and return connections | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 2" int. thread | 2" int. thread | |
Max. operating pressure | bar | 3 | 3 | 3 | 3 | 3 | 3 | 3 |
Energy efficiency class | C | C | C | C | C | C | C |
AccuWIN Klassik: 2 heating coils
Type | ACK 802R | ACK 1002R | ACK 1502R | ACK 2002R | |
Contents | approx. l | 800 | 1,000 | 1,500 | 2,000 |
Coil heater surface top/bottom | m2 | 2.4/1.8 | 3.0/2.4 | 3.6/2.4 | 4.2/2.8 |
Coil heater content top/bottom | l | 15/11 | 19/15 | 22/15 | 26/26 |
ø not including insulation | mm | 790 | 790 | 1000 | 1100 |
Height not including insulation | mm | 1700 | 2050 | 2150 | 2380 |
Height including insulation | mm | 1785 | 2135 | 2235 | 2465 |
Tilted height not including insulation | mm | 1750 | 2090 | 2270 | 2460 |
Weight not including insulation | kg | 146 | 176 | 278 | 341 |
Supply and return connections | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | 6/4" int. thr. | |
Max. operating pressure | bar | 3 | 3 | 3 | 3 |
Energy efficiency class | C | C | C | C |