Compact pre-assembled pump group for fixed point regulation and circulation of mixed fluid. Allows the circulation of the thermal fluid, coming from the primary circuit, by keeping the temperature at a pre-set value (fixed point) through the help of a mixing valve with thermostatic element. Designed for the expansion of heating systems where a new room is added (room, conservatory, extension etc) connecting it to the existing system, typically with radiators, keeping the same heat generator. It is used in heating systems in general and radiant panel systems. The group is composed of a pump, thermostatic mixing valve, control thermostat, connection T-fittings with ball shut-off valve, wall mounting bracket. Flow and return can be easily exchanged from right to left by rotating the thermostatic mixing valve together with the connected T-fittings.