GEMA hot water storage tank for domestic water with 1 heat exchanger (100–180 liters)

Efficient hot water heating

The GEMA hot water tank with integrated heat exchanger offers a central solution for the safe and efficient heating of domestic water. The internal heat exchanger unit harnesses the energy from a solar thermal system or the heat from a boiler, thus ensuring consistently high levels of hot water comfort.

By combining it with your photovoltaic system and an optional heating element, you can further increase your energy yield. This way, you can benefit from independent, environmentally friendly hot water production even on days with little sunshine.

Corrosion protection and durability

For long-term, trouble-free operation, the tank's interior is lined with high-quality enamel. Additionally, a generously dimensioned magnesium sacrificial anode protects the metal from corrosion and significantly extends its service life.

The solid polyurethane foam (PUR) insulation minimizes heat loss and keeps your energy costs low. Even at maximum storage loads of up to 95°C, the material operates reliably and maintains its shape.

Flexibility and connectivity options

The hot water tank has all standard connections: heating and return lines, drinking water supply and return lines, and circulation in ¾" male thread. An additional connection for a 1 ½" electric heating element can be retrofitted to integrate additional heat generators.

This system is compatible with solid-state, wood-fired, pellet-fired, and combi boilers, as well as solar thermal systems. This makes it versatile and adapts flexibly to existing heating concepts.

Technical data and model variants

The storage tank volumes range from 100 to 180 liters and reliably cover the hot water needs of small to medium-sized households. Depending on the model, the heat exchanger surface area varies between 1.2 and 1.67 m², and the exchanger capacity between 5.3 and 7.8 liters.

Maximum operating pressures are 6 bar for the storage tank and exchanger, with a maximum temperature of 95 °C in the storage tank and 100 °C in the exchanger. Heat losses range between 28 and 42 watts, depending on the volume.

Dimensions and weights:

– 100 liters: Ø 625 × 770 mm, empty 64 kg
– 120 liters: Ø 565 × 1045 mm, empty 71 kg
– 150 liters: Ø 625 × 980 mm, empty 76 kg
– 180 liters: Ø 715 × 1030 mm, empty 88 kg

Retrofittable electric heating element

For additional heat requirements, a 1.5 kW, 2.0 kW, or 3.0 kW heating element can be installed. All versions feature a temperature controller (23–75 °C), a safety limiter (85 °C), and operate with an IP44 protection rating.

The electrically insulated design with a plastic housing and temperature-stabilized alloy (Alloy 825) guarantees high corrosion protection. The heating elements are operated single-phase (230 V/16 A) and provide flexible support as needed.

Technical data 100 liter storage tank

• Volume: 100 liters
• Heat exchanger surface: 1.2 m²
• Heat exchanger capacity: 5.27 liters
• Connection flow and return heating: 3/4" AG
• Connection flow and return domestic water: 3/4" AG
• Circulation connection: 3/4" AG
• Magnesium anode connection: 1 1/4" IG
• Connection for electric heating: 1 1/2" IG
• Thermal insulation: polyurethane foam (PUR)
• Max. operating temperature storage 95 °C
• Max. operating pressure storage tank/heat exchanger: 6 bar
• Max.Operating temperature heat exchanger 100 °C
• Loss: 28 watts
• Dimensions with insulation (diameter x height): 625 x 770 mm
• Weight (empty): 64 kg

Technical data 120 liters

• Volume: 120 liters
• Heat exchanger surface: 1.4 m²
• Heat exchanger capacity: 6.1 liters
• Connection flow and return heating: 3/4" AG
• Connection flow and return domestic water: 3/4" AG
• Circulation connection: 3/4" AG
• Magnesium anode connection: 1 1/4" IG
• Connection for electric heating: 1 1/2" IG
• Thermal insulation: polyurethane foam (PUR)
• Max. operating temperature storage 95 °C
• Max. operating pressure storage tank/heat exchanger: 6 bar
• Max. operating temperature heat exchanger 100 °C
• Loss: 32 watts
• Dimensions with insulation (diameter x height): 565 x 1045 mm
• Weight (empty): 71 kg

Technical data 150 liters

• volume: 150 liters
• Heat exchanger surface: 1.4 m²
• Heat exchanger capacity: 6.1 liters
• Connection flow and return heating: 3/4" AG
• Connection flow and return domestic water: 3/4" AG
• Circulation connection: 3/4" AG
• Magnesium anode connection: 1 1/4" IG
• Connection for electric heating: 1 1/2" IG
• Thermal insulation: polyurethane foam (PUR)
• Max. operating temperature storage 95 °C
• Max. operating pressure storage tank/heat exchanger: 6 bar
• Max. operating temperature heat exchanger 100 °C
• Loss: 36 watts
• Inner diameter of storage tank: 510 mm
• Dimensions with insulation (diameter x height): 625 x 980 mm
• Weight (empty): 76 kg

Technical data 180 liters

• Volume: 183 liters
• Heat exchanger surface: 1.67 m²
• Heat exchanger capacity: 7.8 liters
• Connection flow and return heating: 3/4" AG
• Connection flow and return domestic water: 3/4" AG
• Circulation connection: 3/4" AG
• Magnesium anode connection: 1 1/4" IG
• Connection for electric heating: 1 1/2" IG
• Thermal insulation: polyurethane foam (PUR)
• Max. operating temperature storage 95 °C
• Max. operating pressure storage tank/heat exchanger: 6 bar
• Max. operating temperature heat exchanger 100 °C
• Loss: 42 watts
• Inner diameter of storage tank: 715 mm
• Dimensions with insulation (diameter x height): 715 x 1030 mm
• Weight (empty): 88 kg

Technical data heating element 1.5 kW

• Heating output: 1.5 kW
• Temperature range: 5-75°C
• Switch-on hysteresis: 7-10°C
• Installation length: 300 mm
• Unheated length: 70 mm
• Safety temperature limiter: 93°C
• Connection: 1 ½" AG
• Max. operating pressure: 10 bar
• Protection class: IPX4
• Heating coil material: Alloy 825
• Housing material: plastic, white
• Power supply: 230V/16A, single-phase
• Connection cable: 1.5 meters with Schuko plug

Technical data heating element 2.0 kW

• Heating output: 2 kW
• Temperature control: 5-75°C
• Switch-on hysteresis: 7-10°C
• Installation length: 300 mm
• Unheated length: 70 mm
• Safety temperature limiter: 93°C
• Connection: 1 1/2" external thread
• Protection class: IPX4
• Max.Operating pressure: 10 bar
• Outer shell material: plastic, white
• Heating coil material: Alloy 825
• Power supply: single-phase 230 V/16 A
• Cable length: 1.5 meters with Schuko plug

Technical data Heating element 3.0 kW

• Heating output: 3 kW
• Temperature setting: 5°C to 75°C
• Switch-on hysteresis: 7-10°C
• Installation length: 420 mm
• Unheated length: 100 mm
• Safety temperature limiter: 93°C
• Connection: 1 1/2" AG
• Power supply: 400 V
• Protection class: IPX4
• Maximum operating pressure: 10 bar
• Heating coil material: Alloy 825

Scope of delivery

– GEMA hot water tank with heat exchanger and insulation
– Diaphragm safety valve
– Operating and maintenance instructions
– Optional: Selfa electric heating element