A swimming pool arrangement comprising a swimming pool, a heating device for heating water from the swimming pool, as well as a water supply system for supplying water from said swimming pool to said heating device and from said heating device to said swimming pool, wherein said water supply system comprises a three-way valve of a first type and a three-way valve of a second type, wherein - said three-way valve of the first type is arranged to regulate the water supply from said swimming pool towards said heating device, and wherein said three-way valve of the first type is arranged to (i) shutting off the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a first position of said three-way valve of the first type; (ii) opening the water supply towards said heating device and shutting off the water supply towards said three-way valve of the second type, in a second position of said three-way valve of the first type; (iii) opening the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a third position of said three-way valve of the first type; - said three-way valve of the second type is arranged to regulate the water supply from said three-way valve of the first type and/or said heating device towards said swimming pool, characterized in that said three-way valve of the second type is arranged to (i) shutting off the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a first position of said three-way valve of the second type; (ii) opening the water supply from said heating device and shutting off the water supply from said three-way valve of the first type, in a second position of said three-way valve of the second type; (iii) opening the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a third position of said three-way valve of the second type. - said three-way valve of the first type is arranged to regulate the water supply from said swimming pool towards said heating device, and wherein said three-way valve of the first type is arranged to (i) shutting off the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a first position of said three-way valve of the first type; (ii) opening the water supply towards said heating device and shutting off the water supply towards said three-way valve of the second type, in a second position of said three-way valve of the first type; (iii) opening the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a third position of said three-way valve of the first type; (i) shutting off the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a first position of said three-way valve of the first type; (ii) opening the water supply towards said heating device and shutting off the water supply towards said three-way valve of the second type, in a second position of said three-way valve of the first type; (iii) opening the water supply towards said heating device and opening the water supply towards said three-way valve of the second type, in a third position of said three-way valve of the first type; - said three-way valve of the second type is arranged to regulate the water supply from said three-way valve of the first type and/or said heating device towards said swimming pool, characterized in that said three-way valve of the second type is arranged to (i) shutting off the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a first position of said three-way valve of the second type; (ii) opening the water supply from said heating device and shutting off the water supply from said three-way valve of the first type, in a second position of said three-way valve of the second type; (iii) opening the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a third position of said three-way valve of the second type. (i) shutting off the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a first position of said three-way valve of the second type; (ii) opening the water supply from said heating device and shutting off the water supply from said three-way valve of the first type, in a second position of said three-way valve of the second type; (iii) opening the water supply from said heating device and opening the water supply from said three-way valve of the first type, in a third position of said three-way valve of the second type.