Flow Switch - Kärcher HDS 9/50 De Tr1 Service Manual

9.16.2 Flow switch

Illustration for pump types 13/20 and 17/20
The flow switch prevents the burner from switching on in
case of missing or insufficient water volume and thus pro-
tects the booster heater from overheating.
With the gun open and sufficient water flow, the solenoid
piston is pushed against the pressure spring.
The solenoid piston closes the contact of the reed switch.
With warm water operation, this opens the fuel solenoid
valve and the burner ignites.
1 Magnetic piston
Illustration for pump types 9/50 and 13/35
1 Magnetic piston
In case of an insufficient water volume, the flow switch im-
mediately switches the burner off in warm water operation
and back on if the water volume suffices.
In order to operate the device in normal operation, the flow
switch must always work synchronously with the pressure
switch. If only one signal is pending, a malfunction occurs.
English 5.906-736.0 Rev. 00 (07/15)
67