Grundfos MQ Notice D'installation Et De Fonctionnement page 20

Fault
6. The pump
starts when no
water is con-
sumed.
If the pump does not start when the fault has been corrected, contact your pump supplier or
Grundfos for further information.
20
Cause
a) Internal non-return valve is
defective, or the existing pipe-
work is leaking or defective.
Remedy
Clean the valve or fit a new one.