Troubleshooting for NON RETURN VALVE (NRV)
Problem
Valves does
not seal backflow
Leak through
the shaft
Micro switch is
out of function
Reason
1)Foreign object
trapped inside
NRV
Solution
Open NRV top cover (for openable
NRV only) or remove the NRV from
line
Check the presence of foreign
objects
-take them off – clean the parts /
2)Organic /
Back flow leak does
seal
Inorganic
not stop
Check the presence of sediments
sediments on
-clean them with chlorine / acid
valve seal or
Check if parts / seal are damaged
sealing seat
-replace the parts / seal if
necessary *
-replace the NRV if necessary *
3)Shaft sealing
Open plugs of shaft
Replace O –rings and reassemble
is damaged
and check the O-ring *
4)Short circuit
Change limit switch
Open the micro switch and look for
position manually
exposed wires in contact
couple of times, a
Cut damaged wires and reconnect
click can be heard but Replace it if necessary *
the circuit remains
closed
5)Contact does Change limit switch
Open the micro switch and look for
not occur
position manually
cut or disconnected wires
couple of times, a
Cut damaged wires and reconnect
click can be heard but Replace it if necessary *
the circuit does not
close
6)Limit switch
Check whether the
Readjust limit switch wheel location
position /
limit switch is
so that switching will take place at
adjustment is
activated when the
the right timing / flow condition
not correct
system change
position from "no
flow" to "flow" and
vice versa
7)Contacts does Close irrigation valves Add a "counter weight" to the NRV
not cut at "no
manually
to force it to rotate all the way down
flow" condition
-limit switch does not to its seat
stop the pump
* Reference in catalog
Check
Try running irrigation
while knocking with a
hammer on the NRV