 In 1925, locomotive 17 206 was given a "Schmidt-Hartmann" high-pressure boiler with a boiler overpressure of 5.884 MPa (58.84 bar), and the drive was converted to a compound configuration.The increased performance of the H 17 206 designated locomotive compared with the production design did not justify the higher construction costs however; the engine was converted back to the standard design in 1929 and retired in 1936.The two locomotives with running numbers 17 236 and 17 239 were given a medium-pressure boiler in 1933 with a boiler overpressure of 2.452 MPa (24.52 bar), and they were also converted to compound operation at the same time.