One from Fischer caught my eye - 1000 units (kWh) free electricity, with multiple Trustpilot claims to be valid, promising 'free heat'.
All they are is a wall mount electric heater and as we all know, they can only be a maximum of 100% efficient and you pay for all you consume. Nothing to be had for free, so how do they get away with such wild claims and claims to save you money on your electricity bills?
The only way to save on your electric heating bills, is to freeze, or switch to something costing less per kW. It suggests doing away with your pipes (I guess your CH pipes, from a gas boiler?), thus you pay 3x 4x as much for electric heat - how does that save money?