Numatic Hi&Lo NHL15 Original Instructions Manual page 39

If the spray nozzles are blocked, they have been designed to be easily cleaned. Undo the spray nozzle cap (Fig 42)
remove (Fig 43) check the 'O' ring for damage replace if necessary (Fig 44) and clean the nozzles (Fig 45).
Note.
Inspect the O ring seal and replace if necessary (Fig 44).
Located in the bottom of the NuChem / water
tank is a barrel filter (Fig 41).
Clean if necessary.
Fig 41
Ensure the machine is cleaned and all hoses and tubes are
flushed with cold clean water.
After use, ensure the solution tube has been flushed
with clean water for at least 60 seconds.
Blocked nozzles
Fig 42
Fig 44
Fig 43
Fig 45