The MAXI series is the class-leading commercial range of hot water calorifiers, built to the high standards of design and efficiency that is synonymous with OSO Hotwater products. The MAXI range has been manufactured with EVERLAST™ high-alloy stainless steel in combination with ULTRAWELD™ technology for optimal corrosion resistance. Not only is the MAXI range extremely efficient, with industry-leading performance, it can also be modified according to customer requirements.

MAXI XPRESS — MX boasts twice the available immersion heater capacity as the standard, is heated either with the integrated electric INCOTEC immersion heaters, or via an external energy source and the TURBOSYSTEM with plate heat exchanger (optional capacity) and double sets of pumps for extra operational safety. The electric immersion heaters has optional effect 5–30 kW, 230–400 V + N 3-phase, and is thermostat controlled 60–90 °C in three steps with separate safety thermostats. Contactors are not required and the support cable is connected directly to the central.

G3 Kits and expansion vessel as standard

Other sizes and specifications are available to order.

• Extreme operational durability with el. heaters w/o contactors
• 10 bar design pressure and class-leading corrosion resistance



  • Specifications
  • Documents
SpecificationsUNITMX 400 – 15 + 15 kW / 3 × 230 VMX 600 – 15 + 15 kW / 3 × 230 VMX 1000 – 15 + 15 kW / 3 × 230 V
Product no.OSO800165280016528001654
Product nameMX 400 - 15 + 15 kW / 3 × 230 VMX 600 - 15 + 15 kW / 3 × 230 VMX 1000 - 15 + 15 kW / 3 × 230 V
Diameter — ⌀mm5957801000
Height - Hmm168519102115
Weight emptykg
Technical/ErP information
Capacity 40CL
Thermostat set pointC606065
Heat loss-EN 12897watt103120142
Heat loss / 24 hrs - EN 12897kWh/day2,472,88
AEC (energy consumption)kW/year
Energy efficiency%
Tapping profile3XS–XXL
Energy ratingA+–FCCC
Primary Heating PowerkW
Primary coil sizeMins
Immersion Heating Power
Heat-up time ΔT 55°C CoilMins
Heat-up time ΔT 55°C upper elementMins
Heat-up time ΔT 55°C lower elementMin
Recovery time ΔT 55°C coil 70%Mins
Recovery time ΔT 55°C upper element 70Mins
Recovery time ΔT 55°C lower element 70%Mins