Heating bath circulation thermostats with a stainless steel bath allow the temperature control of internal and external thermo-regulation tasks. Items can be directly thermo-regulated by placing them in a thermostat bath and the control of externally connected applications is also possible. The units are suitable for a number of typical temperature control tasks such as sample temperature control, materials testing, quality control, etc. The devices are fitted with over-temperature and low level protection in line with Safty Class III/FL according to DIN 12876. A powerful pressure/suction pump ensures optimal circulation and temperature homogeneity in the thermostat bath and also allows temperature control of externally connected applications.