Elix PV Water Heater – 150L/200L

Elix PV water heater designed for direct connection with solar (PV) panels. The PV boiler uses direct current (DC) water heating element to convert solar energy into hot water. The DC heating element connects directly to Solar panels with MC4 connectors with no inverter and, no grid registration required. Boiler also uses 230V (AC) water heating element when solar DC power is insufficient.

Elix PV water heater can be equipped with Elix MPPT controller that increases pv panels energy yield by up to 30%.

Features

• Integrates both DC and AC water heating elements.
• Supports Solar (DC-only) and Hybrid (DC+AC) modes.
• 100% utilization of solar energy – no excess is lost.
• Ensures consistent water temperature
• No inverter needed – direct connection to solar panels
• Simple installation
• 54mm insulation – best in class!
• MPPT controller with Wi-Fi can be equipped.
• Suitable for indoor (recommended) or outdoor installation.
• Warranty:
  • 5 years (water tank)
  • 2 years (electrical components)

Water Heater Characteristics (150L/200L)

• Inner tank material: Enameled BTC340R steel
• Thickness of inner tank: 2.5mm
• Insulation Thickness: 54 mm
• Outer Tank Material: Anti-corrosion steel
• Rated Pressure: 0.8 MPa
• Dimensions:
  • 150L: Ø520 x 1308 mm
  • 200L: Ø520 x 1688mm
• Water pipes size: G3/4 ’’
• temperature: 75 °C
• Air duct diameter: 160mm
• DC heater power: depends on solar panels setup
• DC heater open circuit voltage limit (Voc): 110V
• DC heater fixed resistance: 6.48 Ω
• AC heater power: 2000W
• AC heater voltage/frequency: 230V/50Hz

* To see how to calculate DC heater power for your set of solar panels check out the pdf manual down below.

How It Works

The boiler uses 2 water heating elements: AC and DC elements. DC heating element is connected directly to solar panels (no need for inverter). AC heating element is connected to a standard 230 V wall socket. If DC solar energy isn’t enough, the AC (230V) can be used for consistent hot water—cloudy or sunny, day or night.

Heating Modes

DC-Only Mode (Solar Heating):

• In this mode, the heater uses only solar energy — no household power is consumed.
• Activated by setting the thermostat knob to “OFF” position.
• In this mode you can’t select an exact water temperature — the water simply heats as much as the sunlight allows.

Hybrid Mode (DC + AC):

• Hybrid mode is active whenever you select temperature with the thermostat knob.
• Hybrid mode uses both AC and DC to ensures fast heating to your chosen temperature
• Automatically switches to DC-only mode when there is enough solar energy to heat water above the temperature selected on thermostat (up to 75°C)

How to select solar panels for your Elix PV water heater

It’s recommended to select solar panels with total power ~ 1300W, that will give the most heating power while keeping the voltage safe (110V) to ensure DC water heater elements doesn’t break.

Complete instruction with calculations on how to select best solar panels setup can be found in the pdf manual down below.

Optional Elix MPPT controller with Wi-Fi

All Elix PV water heater models can be equipped with Elix MPPT controller. It continuously tracks the maximum power point of the solar panels for enhanced solar energy gains of up to 30%:

• Allows to control your Elix PV water heater with your phone (SmartLife app)!
• PV power/voltage monitoring, mode switching, temperature adjustment.
• Provides additional operating modes for PV water heater

How to Connect to Solar Panels

Solar panels are simply connected with MC4 cables directly to the water heater. There’s no need for an inverter, simplifying installation and reducing costs.

Additionally, water heater needs to be connected to AC 230V socket to provide power for AC water heating element

How to Connect to Solar Panels with MPPT

• PV panels and 230V AC grid connect to the controller’s input.
• Controller outputs connect to the water heater’s DC (direct solar) and AC (grid-assisted) heating elements.

No Solar Energy Wasted

The Elix PV water heater acts as a battery that stores solar energy as hot water. When there’s plenty of sunshine but low hot water demand, it uses DC heating only mode, which converts surplus solar energy into hot water (up to 75 °C). 54mm insulation ensures minimal heat loss.

Instead of wasting excess solar energy, the system stores it as hot water for later use on cloudy days or at night—eliminating the need to send surplus electricity through an inverter or back to the grid.

DC only heating performance

The table below shows how much 55 °C hot water (liters per hour) the boiler can continuously supply in DC only heating mode with different power outputs from PV panels.

This helps to see what to expect under various sunlight conditions and solar panel sizes.

Conditions

• AC heating element inactive
• DC heating element active
• Water in tank is already heated up to 55 °C
• Cold inlet water temperature: 15 °C
• Target hot water temperature: 55 °C
• Ambient room temperature: 20 °C

* To see how to calculate DC heating power for your set of solar panels check out the pdf manual down below.

Advantages of the ELIX PV Heating System

• Inverter-Free Operation: Direct connection to solar panels via MC4 connectors minimizes installation cost and complexity.
• No Grid Registration: No inverter or grid connection required for PV panels.
• Dual Heating Mechanism: Integrates both DC and AC heating elements for reliable operation across varying sunlight conditions.
• Thermal Energy Storage: Functions as an energy battery, storing excess solar energy in the form of hot water.
• Thick insulation: 54mm insulation ensures minimal heat loss for efficient hot water storage.
• Robust Construction:  Enameled BTC340R steel inner tank and anti-corrosion steel outer shell ensure durability for up to 20 years.

PV vs Solar-Thermal water heating systems

Unlike solar-thermal systems that require pumps, pipes, and coolant, the Elix PV Water Heater uses solar panels to directly power the tank’s heating element, eliminating leaks, gasket issues, and other maintenance bottlenecks.

• Low maintenance: Requires minimal upkeep compared to solar-thermal systems.
• Longer lifespan: PV panels last 20–25 years, versus 10–15 years for solar-thermal collectors.
• Lower costs: Overall system costs can be 30–40% lower.
• Simple installation: Fewer components make setup easier and faster.

The Elix PV system is a simpler, more cost-effective, and durable solution for sustainable water heating.

Maintenance

Rust Protection Magnesium Anode – Protects the inner tank surface from corrosion. The anode wears over time and must be inspected and replaced every 24 monthes.