Grundfos SMART Digital DDA, Installation And Operating Instructions Manual

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8.1.2 General faults
9. Disposal
This product and all its associated parts must
be disposed of in an environmentally friendly
manner. Use appropriate waste collection
services. If there is no such facility or the facility
refuses to accept thse materials used in the product,
the product can be sent to the nearest Grundfos
company or Grundfos service centre.
Fault Possible cause Possible remedy
Dosing flow too high
Inlet pressure greater than
backpressure
Install additional spring-loaded valve
(approx. 3 bar) on the discharge side.
Increase pressure differential.
Incorrect calibration
Calibrate the pump (see section 5.3 Calibrating
the pump ).
No dosing flow or
dosing flow too low
Air in dosing head Deaerate the pump.
Faulty diaphragm
Change the diaphragm (see section 7.2 Perform
service ).
Leakage/fracture in lines Check and repair lines.
Valves leaking or blocked Check and clean valves.
Valves installed incorrectly
Check that the arrow on the valve housing is
pointing in the direction of flow. Check whether all
O-rings are installed correctly.
Blocked suction line Clean suction line/install filter.
Suction lift too high
Reduce suction lift.
Install priming aid.
Enable 'Slow Mode’ (see section 6.6 SlowMode ).
Viscosity too high
Enable 'Slow Mode’ (see section 6.6 SlowMode ).
Use hose with larger diameter.
Install spring-loaded valve on the discharge side.
Pump outside the calibration
Calibrate the pump (see section 5.3 Calibrating
the pump ).
Deaeration valve open Close the deaeration valve.
Irregular dosing
Valves leaking or blocked
Tighten up valves, replace valves if necessary
(see section
7.2 Perform service ).
Backpressure fluctuations
Keep backpressure constant.
’AutoFlowAdapt’ activate (only FCM).
Liquid escaping from
the discharge opening
on the flange
Faulty diaphragm
Change the diaphragm (see section 7.2 Perform
service ).
Liquid escaping
Dosing head screws not
screwed in as far as they will go Tighten up screws (see section 4.2 Hydraulic
connection ).
Valves not screwed in as far as
they will go Tighten up valves/union nuts (see section
4.2 Hydraulic connection ).
Pump not sucking in
Suction lift too high
Reduce suction lift; if necessary, provide positive
inlet pressure.
Backpressure too high Open the deaeration valve.
Soiled valves
Flush system, replace valves if necessary
(see section
7.2 Perform service ).
Subject to alterations.