What type of installation is needed to install a patio heater and can I do it myself?
Above 3kW and it is a job for a qualified electrician. Below that, wall mounted units can be fixed by anyone with the ability to drill a few holes and put a plug in.
When using a 3kW heater in commercial premises or other locations where the heaters are used continuously for long periods of time then it is advisable to consult an electrician. A 3kW heater used for long periods of time may need to be hard wired into a 20A fused spur rather than used in a standard 13A socket.