Can a 3 kW immersion heater be connected to a 13 A fused connection unit to BS 1363-4?

According to the Institute of Electrical Engineers (IET):

Immersion heaters rated 3 kW at 240 V are generally unsuitable for connection via a connection unit to BS 1363-4, unless the manufacturer of the connection unit confirms otherwise. They are also generally unsuitable for connection via a plug and socket-outlet combination to BS 1363-1 and BS 1363-2.

Immersion heaters rated 3 kW, at a nominal voltage of 230 V, are unsuitable for connection via a protective device with a nominal current rating less than 15 A. They should therefore not be connected via plugs and socket-outlets, or connection units, to BS 1363 series, as this presents a likely risk of fire or overheating.

It is recommended that, unless the manufacturer of a fused connection unit confirms otherwise:

In general, the maximum domestic appliance loads that use full power for periods above 30 minutes, connected to BS 1363 plugs and fused connection units, is limited to 2.7 kW (11.7 A).

NOTE: Some appliances supplied with a BS 1363 plug, such as tumble dryers and kettles, can be rated above 2.7 kW; however, these appliances only use their full rated power for relatively short periods of time.

Fused connection units to BS 1363-4, and socket-outlets to BS 1363-2, are not located where they will be subject.