7
Troubleshooting
Pump Troubleshooting Guide
Thermo Scientific
Accela Pump Hardware Manual
85
6. Proportioning
valves do not
click
a. Loose actuating coil
a. Reattach the actuating coil (see
page 61
)
b. Defective proportioning valve
b. Contact your Thermo Fisher Scientific service
representative
c.
Defective proportioning valve
drive circuit
c.
Contact your Thermo Fisher Scientific service
representative
d. Proportioning valves are stuck
d. See
“Servicing the Proportioning Valves”
on
page 77
7. Erratic flow rate
a. Restricted inlet tubing
a. Replace the inlet tubing
b. Restricted outlet tubing
b. Replace the outlet tubing
c.
Dirty proportioning valve
c.
Flush the LDA with the appropriate solvents (see
“Cleaning the LDA Components without
Disassembling the LDA”
on
page 56
) or replace
the proportioning valves
d. Dirty check valve
d. Flush the LDA with the appropriate solvents (see
“Cleaning the LDA Components without
Disassembling the LDA”
on
page 56
) or replace
the check valves
e.
Leaking piston seal
e.
Replace the piston seals (see
“Replacing the
Primary Pistons Seals”
on
page 67
)
f.
Clogged solvent reservoir filter
f.
Replace the filter (see
“Replacing the Solvent
Reservoir Filters”
on
page 79
)
8. No flow
a. Loose or disconnected solvent
lines
a. Check for leaks in the solvent lines at the
degassing inlets and outlets, the proportioning
valve inlets, and the crossover tube connections
b. Excessive air in the solvent lines b. Remove the air from the solvent lines (see
“Removing Air from the Solvent Lines”
on
page 37
)
c.
Open venting valve
c.
Close the venting valve on the left side of the
LDA
Table 7.
Troubleshooting pump-related problems (Sheet 2 of 2)
Problem
Cause
Diagnostic/Remedy
