The Marylebone sets, which were later transferred to Bletchley but remained on Chiltern Line duties, were declared surplus after the introduction of Class 165s, from '91 onwards. While at Bletchley depot the class was also used on the Barking to Gospel Oak line, units being formed as power twins.  They were in turn replaced on this line by class 117 power twins.

The final Class 115 working out of Marylebone was in July '92. The Tyseley sets survived a bit longer until Feb '94.