... for close-loop solar heating system 2) It includes electric controller, circulation pump, safe valve, relief air valve, pressure meter, ... you comfortable to use this systemII. Components of the working controller:1) Circulation pump (WILO) 2) Flow meter(import from ... Switzerland) 3) Check valve 4)Manometer 5) Automatic controller 6) Safety valve 7) Ball valveComponents: 1) Circulation pump ...