I have an iboost+ and it does seem to work well, however my immersion heater is too short, so really I need the heater swapping for a longer one.
I found I needed to adjust the point where it kicks in, seems the CT coil was too close to another CT coil and they were interfering with each other, but the adjustment seemed to work and I think one does need one where you can fine tune it to your system.
Considering what it does it is compact, it seems it can vary the energy used from around 100 watt to the full 3 kW did not know any other makes existed.
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