Boiler-filter assembly comprising a boiler and a filter suitable for filtering the water that flows into the boiler in order to remove any residues from the water; said filter comprising: - a cylindrical body comprising a lateral surface , a first end wall , a second end wall and a longitudinal axis (X); said body comprising a first mouth and a second mouth obtained on the lateral surface ; said first mouth being intended to be connected to a water system and said second mouth being connected to the boiler ; - a pipe arranged in the body in communication with the exterior; - a magnet inserted in the pipe to hold ferrous residues contained in the water; said boiler-filter assembly comprising a three way valve comprising: - a first port connected to the first mouth of the body ; - a second port intended to be connected to the water system; - a third port used to discharge the water; - a diverter suitable for being in a first position, wherein the diverter closes the third port of the three way valve , and in a second position, wherein the diverter closes the second port of the three way valve ; wherein said first mouth and said second mouth of the body of the filter are tangent to the body , being aligned and disposed on the same side of the body relative to a plane passing through the longitudinal axis (X) of the body of the filter; characterized in that said filter comprises: - a drum suitable for holding non-ferrous residues; and - a disk disposed in the pipe and comprising a plurality of openings with variable helical geometry. - a cylindrical body comprising a lateral surface , a first end wall , a second end wall and a longitudinal axis (X); said body comprising a first mouth and a second mouth obtained on the lateral surface ; said first mouth being intended to be connected to a water system and said second mouth being connected to the boiler ; - a pipe arranged in the body in communication with the exterior; - a magnet inserted in the pipe to hold ferrous residues contained in the water; said boiler-filter assembly comprising a three way valve comprising: - a first port connected to the first mouth of the body ; - a second port intended to be connected to the water system; - a third port used to discharge the water; - a diverter suitable for being in a first position, wherein the diverter closes the third port of the three way valve , and in a second position, wherein the diverter closes the second port of the three way valve ; - a first port connected to the first mouth of the body ; - a second port intended to be connected to the water system; - a third port used to discharge the water; - a diverter suitable for being in a first position, wherein the diverter closes the third port of the three way valve , and in a second position, wherein the diverter closes the second port of the three way valve ; wherein said first mouth and said second mouth of the body of the filter are tangent to the body , being aligned and disposed on the same side of the body relative to a plane passing through the longitudinal axis (X) of the body of the filter; characterized in that said filter comprises: - a drum suitable for holding non-ferrous residues; and - a disk disposed in the pipe and comprising a plurality of openings with variable helical geometry. - a drum suitable for holding non-ferrous residues; and - a disk disposed in the pipe and comprising a plurality of openings with variable helical geometry. <EOS>