ICRF mode conversion has been developed for localised on-axis and off-axis bulk electron heating on the JET tokamak. The fast magnetosonic waves launched from the low-field-side ICRF antennas are mode-converted to short-wavelength waves on the high-field side of the 3He ion cyclotron resonance layer in D and 4He plasmas and subsequently damped on the bulk electrons. The resulting electron power deposition, measured using ICRF power modulation, is narrow with a typical full width at half maximum of 30cm (i.e. about 30% of the minor radius) and comprises at least up to 80 % of the applied ICRF power. The ICRF mode conversion power deposition has been kept constant using 3He bleed throughout the ICRF phase with a typical duration of 4-6s, i.e. 15-40 energy confinement times. Using waves propagating in the counter-current direction minimises competing ion damping in the presence of co-injected deuterium beam ions.