A method and apparatus are disclosed for applying negative pressure to a wound site. The apparatus comprises a source of negative pressure, a processing element, and a memory comprising instructions configured to, when executed on the processor, cause the apparatus to perform the steps of, via the source of negative pressure, attempting to generate a desired negative pressure at the wound site, if the desired negative pressure has not been generated after a first predetermined period of time, deactivating the source of negative pressure for a second predetermined period of time, and subsequently attempting to generate the desired negative pressure at the wound site.
