25
Maintenance
PROBLEM
POSSIBLE CAUSE
SOLUTION
SYSTEM WILL NOT
COME UP TO FULL
DESIGNATED
PRESSURE
Spray nozzle worn or nozzle orifice
is too large in relation to pump flow
rate
See serial plate for correct nozzle size.
Adjusted improperly
Readjust unloader with pressure gauge.
Bypass valve (within unloader) is
obstructed or leaking
Remove and clean bypass cartridge or replace.
Flow rate of pump inadequate
Assure designated flow rate of pump is
adequate in relation to spray nozzle size.
PRESSURE SPIKES IN
DISCHARGE LINE
DURING BYPASS MODE
Pressure adjustment too tight
Call your local dealer.
Restricted bypass line
Bypass line should be 1/2" inside diameter
(I.D.), 12" long and of low pressure flexible
hose.
Flow rate higher than 8 gpm
Unloader flow rate is 7.8 gpm maximum.
UNLOADER CYCLES
WHILE IN BYPASS
MODE
External leak on unloader or in
downstream fittings
Inspect all high pressure lines (including spray
gun and hose) for any signs of leakage and
repair as necessary.
Discharge valve (within the
unloader) damaged, obstructed or
worn
Inspect and replace as necessary.
Weep gun is being used
The unloader is not designed for use with a
weep gun.
Landa PHW Operator’s Manual 8.917-417.0 - E