I noticed in Teacup firmware that they have this;
/** \def HEATER_SANITY_CHECK
check if heater responds to changes in target temperature, disable and spit errors if not
largely untested, please comment in forum if this works, or doesn't work for you!
*/
// #define HEATER_SANITY_CHECK
As it says it is mostly untested but should do basically what you want, If it works.
Forum:
RAMPS Electronics