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 COIL — MC is ideal for direct electric operation during summer and can be switched to boiler operation during winter. MAXI COIL comes standard with a smooth-piped, scaleesistant heating coil with a capacity of up to 30 kW from the boiler. The electric immersion heaters have optional effect 5–15 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 kit and Vessel can be supplied.

Other sizes and specifications are available to order.

• Energy flexibility for summer / winter operation, or as back-up
• Extreme operational durability with el. heaters w/o contactors
• 10 bar design pressure and class-leading corrosion resistance



  • Specifications
  • Documents
SpecificationsUNITMC 400 – 15 kW / 3 × 230 V + HX 1,0 m²MC 600 – 15 kW / 3 × 230 V + HX 1,0 m²MC 1000 – 15 kW / 3 × 230 V + HX 1,0 m²
Product no.OSO
Product nameMC 400 - 15 kW / 3 × 230 V + HX 1,0 m²MC 600 - 15 kW / 3 × 230 V + HX 1,0 m²MC 1000 - 15 kW / 3 × 230 V + HX 1,0 m²
Diameter — ⌀mm
Height - Hmm
Weight emptykg
Technical/ErP information
Capacity 40CL
Thermostat set pointC
Heat loss-EN 12897watt
Heat loss / 24 hrs - EN 12897kWh/day
AEC (energy consumption)kW/year
Energy efficiency%
Tapping profile3XS–XXL
Energy ratingA+–F
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