A degassing and de-aerating module for a dialysate flow path, comprising: a flow-through chamber and a gas collection chamber that in use is arranged above the flow-through chamber, the degassing and de-aerating module further comprising a hydrophobic vent membrane separating the flow through chamber and the gas collection chamber and forming a portion of the flow-through chamber and the gas collection chamber, wherein the flow-through chamber having an upper port that is a fluid inlet port and a lower port that is a fluid outlet port, wherein the hydrophobic vent membrane is positioned at a higher elevation on the flow-through chamber than the fluid outlet port and wherein fluid flows through the flow-through chamber in a downward direction relative to the hydrophobic vent membrane; and wherein the gas collection chamber has a vent port in fluid communication with a gas outlet port, which is in communication with the atmosphere; and wherein the degassing and de-aerating module further comprising a vent control valve fluidly arranged between the vent port and the gas outlet port and operable to permit or allow gas to enter or exit the gas collection chamber; and further operable to permit or allow gas to enter or exit the flow-through chamber via the hydrophobic vent membrane, and wherein the vent control valve, when closed, prevents air entry into the flow-through chamber through the hydrophobic vent membrane and wherein the vent control valve when opened allows gas to exit out of the flow-through chamber through the hydrophobic vent membrane; and wherein the degassing and de-aerating module is configured that, when the pressure in the degassing and de-aerating module drops below atmospheric pressure and the vent control valve is closed, air is prevented to enter into the gas collection chamber and flow-through chamber; and wherein the degassing and de-aerating module is characterized in that, when the pressure in the degassing and de-aerating module drops below atmospheric pressure and the vent control valve is opened, air is allowed to enter into the gas collection chamber and flow-through chamber from the atmosphere. a flow-through chamber and a gas collection chamber that in use is arranged above the flow-through chamber, the degassing and de-aerating module further comprising a hydrophobic vent membrane separating the flow through chamber and the gas collection chamber and forming a portion of the flow-through chamber and the gas collection chamber, wherein the flow-through chamber having an upper port that is a fluid inlet port and a lower port that is a fluid outlet port, wherein the hydrophobic vent membrane is positioned at a higher elevation on the flow-through chamber than the fluid outlet port and wherein fluid flows through the flow-through chamber in a downward direction relative to the hydrophobic vent membrane; and wherein the gas collection chamber has a vent port in fluid communication with a gas outlet port, which is in communication with the atmosphere; and wherein the degassing and de-aerating module further comprising a vent control valve fluidly arranged between the vent port and the gas outlet port and operable to permit or allow gas to enter or exit the gas collection chamber; and further operable to permit or allow gas to enter or exit the flow-through chamber via the hydrophobic vent membrane, and wherein the vent control valve, when closed, prevents air entry into the flow-through chamber through the hydrophobic vent membrane and wherein the vent control valve when opened allows gas to exit out of the flow-through chamber through the hydrophobic vent membrane; and wherein the degassing and de-aerating module is configured that, when the pressure in the degassing and de-aerating module drops below atmospheric pressure and the vent control valve is closed, air is prevented to enter into the gas collection chamber and flow-through chamber; and wherein the degassing and de-aerating module is characterized in that, when the pressure in the degassing and de-aerating module drops below atmospheric pressure and the vent control valve is opened, air is allowed to enter into the gas collection chamber and flow-through chamber from the atmosphere.