Stop Heater problems
Heater breakes easily
The heater is made of glass and break easily. Handle it as an instrument and never put it on a hard surface (put a towel under) and this will not be any problem.

Very most important: before taking the heater up from the mash it must have been turned off for at least 15 minutes, prefereably one hour. If it is hot, glass will split when the heater is removed from the liquid.