Bypass valve with an integral flow sensor for a water treatment system

A bypass valve for a water treatment system comprising:

• a body having a first chamber, a second chamber connected by a bridge passage to the first chamber, an inlet that opens into the first chamber to receive untreated water, an untreated water outlet that opens into the first chamber, a treated water inlet that opens into the second chamber, and an outlet that opens into the second chamber and through which treated water flows;
• a first valve element rotatably received in the first chamber and having a first position in which the inlet is connected to the untreated water outlet, and a second position in which the inlet is connected to the bridge passage and disconnected from the untreated water outlet;
• a second valve element rotatably received in the second chamber and having a third position in which the treated water inlet is connected to the outlet, and a fourth position in which the outlet is connected to the bridge passage and disconnected from the untreated water outlet, wherein at least one of the first valve element in the first position and second valve element in the third position blocks flow of water through the bridge passage;
• a manually operable mechanism to rotate the first valve element in the first chamber and the second valve element in the second chamber;
• and
• a sensor located in one of the first chamber and the second chamber and producing an indication of how much fluid flows through the bypass valve.