fothermo
1 kW solar immersion heater
Hot water from solar power. Less gas and oil.
1 kW solar immersion heater for 2–4 people. Connect solar panels directly – no inverter needed.
- Take care when choosing your solar panelsThe MPP voltage (Vmpp) determines the available power. The open-circuit voltage (Voc) must not exceed 50 V. Check MPP voltage ›
- Take care when choosing the inverterFor feeding into the grid, only use micro inverters from our whitelist. View whitelist ›
- Up to 99% efficiencyPatented MPP tracker for maximum use of solar power.
- Plug & PlayNo inverter. No electrician. Direct DC use.
- Digital displayPower and temperature always in view.
- Tested & certifiedSafe, durable and approved for drinking water.
At a glance
More sun. Lower heating bills.
* Guide values. Actual savings depend on water consumption, weather and heating system.
How it works
Hot water first. Then into the grid.
The 1 kW solar immersion heater heats your water first. Once the tank is hot, the surplus flows into the grid via an inverter.
Installation
Installed in minutes.
Screw in
Fits horizontally into your hot water tank with the standard G 1½″ thread.
Plug in
Connect the solar panels in parallel via solar connectors. No inverter, no electrician.
Done
The MPP tracker adjusts the power continuously and stops automatically at the target temperature.
Specifications
Every detail.
- Heating power
- up to 1,000 W
- Recommended PV power
- 1,500–2,500 Wp (usually 4 panels)
- Panel voltage
- Voc max. 50 V · Vmpp 38–43 V Check MPP voltage ›
- Wiring
- Panels in parallel
- Thread
- G 1½″ (6/4″)
- Length / immersion depth
- 315 mm / 295 mm
- Surplus output
- for an optional micro-inverter
In the box
- 1× 1 kW solar immersion heater
- 1× operating manual
- 2× solar connector pairs
Weiterlesen
- A summer break for your heat pump Read article ›
- MPP voltage: how much power you get from your panels. Read article ›
Downloads
- Manual 1 kW Solar Immersion Heater Preview & download
- fothermo Datasheet 1 kW solar immersion heater EN V1 Preview & download
FAQ
Frequently asked questions.
Which heating systems is the 1 kW solar immersion heater suitable for?
As a supplement to gas, oil and pellet heating as well as log boilers. Depending on the set-up, also together with a heat pump. Your existing heating stays in place.
Which solar panels do I need?
Panels with an open-circuit voltage below 50 V (Voc) and an operating voltage of 38–43 V (Vmpp). A total of 1,500–2,500 Wp is recommended, usually four panels. The panels are connected in parallel – series connection is not permitted.
Will the 1 kW solar immersion heater fit my tank?
The 1 kW solar immersion heater has a standard G 1½″ thread (also called 6/4″) and is installed horizontally. Length 315 mm, immersion depth 295 mm. Check the thread on your tank before buying.
Do I need an inverter, battery or 230 V connection?
No. The 1 kW solar immersion heater connects directly to the panels. Optionally, a micro inverter can be connected to the surplus output: once the water is hot, surplus solar power flows into your home grid.
Does it work when it's cloudy?
Yes. Panels also generate power in diffuse light, just less. The control adjusts automatically. If there isn't enough sun, your existing heating takes over as usual.
Hot water, paid for by the sun.
We'll advise you personally – and find the solution that fits your home.