Hot water thermoregulation unit using secondary circuit or indirect system, to which a classic heating process is combined (burner or electrical); these units use hot primary fluid, deriving from a distribution line already present, to thermoregulate the secondary fluid to the utilities, with the alternative possibility of directly heating it. The bivalent systems are used to thermoregulate pasteurizers (food sector), injection moulds (plastic, aluminium, etc.), extruders, heated press platens, hot rolling systems, cylinders for textile calenders, tanks, baths and many other applications. The double power supply of this system allows the end user to have vast flexibility of use. Heaters electronically managed using a micro-processor system, equipped with a utilities circuit circulation pump, heating elements, expansion tank, power panel, control panel, heat exchangers or mixing units at high efficiency and certified control and safety systems. Available in versions for design temperatures up to 110°C and powers up to 5000 kW. The equipment is supplied in a compact mono-bloc version, with a palletised support and the possibility of lifting using eyebolts.