21
Maintenance
PROBLEM
POSSIBLE CAUSE
SOLUTION
BURNER
WILL
NOT LIGHT
(continued from
previous page)
Clogged burner nozzle
Clean as required.
Thermostat faulty or slow engine speed
Increase engine RPM to increase voltage.
Flow switch malfunction
Remove, test for continuity and replace as
needed.
Flow solenoid malfunction
Replace if needed.
25 Amp circuit breaker tripped
Push reset button.
Bridge rectifier defective
Test and replace.
12V DC relay defective
Test and replace.
Fuel is not reaching combustion
chamber
Check fuel pump for proper flow. Check
solenoid flow switch on machines with spray gun
control for proper on-off flow control.
MACHINE
SMOKES
WHILE
BURNER UNIT
IS RUNNING
OR
UNIT SMOKES AT
COLD-START
ONLY WHEN
BURNER IS OFF
Improper fuel or water in fuel
Drain tank and replace contaminated fuel.
Improper air adjustment
Readjust air bands on burner assembly.
Low fuel pressure, below 140 psi
Adjust fuel pump pressure to specifications.
Plugged or dirty burner nozzle
Replace nozzle.
Faulty burner nozzle spray pattern
Replace nozzle.
Heavy accumulation of soot on coils and
burner assembly
Remove coils and burner assembly, clean thor-
oughly.
Misaligned electrode setting
Realign electrodes to specifications.
Obstruction in smoke stack
Check for insulation blockage or other foreign
objects.
Low engine RPM
Increase RPM.
High fuel pressure, if above 140 psi, when
unit is cold-started and burner is off
Adjust fuel pump pressure down and/or adjust air
band higher
LOW
WATER
TEMPERATURE
Improper fuel or water in fuel
Replace with clean and proper fuel.
Low fuel pressure
Increase fuel pressure.
Weak fuel pump
Check fuel pump pressure. Replace pump if
needed.
Fuel filter partially clogged
Replace as needed.
Soot build-up on coils not allowing heat
transfer
Clean coils.
Improper burner nozzle
See specifications.
Landa MHP Operator’s Manual 8.913-925.0 - T