We present a multi-instrument analysis of a B7.9 class flare which was observed on January 24th, 2015 using SDO/AIA, Hinode/EIS and XRT. The flare heats the local plasma up to a temperature of ~6 MK, and triggers the eruption of a dense blob, which is unable to completely breaks out and remains confined within the local bundle of active region loops. During this process, vertically polarised kink oscillations of the loop threads with a period of 3 min and an amplitude of 4 Mm are driven by the blob, which diffuses and descends along each loop strand causing density variations estimated around 30-50%. In addition, a co-existing longitudinal slow MHD wave propagates along the hot loop bundle with a period of 10 min and a phase speed of 150 km/s. We show that the evolution of these waves are determined by the temporal variations of the local plasma parameters, caused by the flare heating and the consequent cooling, and both waves contribute to straightforward results in coronal seismology.