English 5.906-736.0 Rev. 00 (07/15) 571 Casing2 Valve3 SpringIf pressure is applied to the casing (1) during operation ofthe pump, the valve (2) closes and no flow is possible.In low pressure operation the spring (3) pushes onto thevalve (2) so that the gate of the valve is opened. As a re-sult, water flows through the overflow valve back to thefloat container. In the frost protection mode water isflushed this way and Glysantin is filled in.Upon starting work (until pressure has built-up) water alsoflows from the valve into the return line, which has a posi-tive effect for the bleeding of the pump.NOTEIf the valve is defective, the maximum pump pressure is nolonger reached. In this case, the valve must be renewed.1 Casing2 Piston3 Spring4 Tappet5 DiaphragmIf pressure is applied to the casing (1) during operation ofthe pump, the piston (2) is pressed against the spring (3)and pushes the tappet (4) onto the membrane (5). Thisway, the pressure switch is operated.In work brakes the spring (3) pushes back the piston (2) sothat the tappet is moved down and releases the pressureswitch.ATTENTIONRisk of property damage! If water or moisture should leakfrom the component, it must be replaced entirely.Replacing the O-rings only does not provide a remedy inthe long run.9.14.2 Function frost protection valve9.14.3 Function pressure switch
