Appendix 7: Troubleshooting
Product Service 1-800-522-7658
58
Original instructions
PROBLEM
CAUSE
CORRECTIVE ACTION
Airflow Alert goes
off and/or there is a
slight decrease in
filter life gauge
HEPA filter loading
The gauge reading steadily decreases as
the cabinet is used.
Blockage of the
return air slots or
grille
Check all return air slots and grilles to
ensure that they are not blocked or
restricted.
Blockage of the
exhaust outlet
Ensure that the exhaust outlet is not
blocked or restricted.
Blockage or
restriction under the
work surface
Ensure that the towel catch and plenum
beneath the work surface are
unobstructed.
Contamination of
work in the cabinet
Improper technique
or procedure for the
biosafety cabinet
See “Use of the cabinet” section in the
manual.
Restriction of the
return air slots or
grille – blockage of
the exhaust outlet
Ensure that all return air slots, grilles
and the exhaust outlet are unobstructed.
External factors are
disrupting the cabinet
airflow patterns or
acting as a source of
contamination
See “Working in the Biosafety
Cabinet” section of this manual.
Cabinet is out of
adjustment/HEPA
filter(s) are defective
Have cabinet recertified.
Exhaust Alarm goes
off
Roof blower is off
Ensure that roof blower is working.
Remote blower is
improperly sized
Confirm that the roof mounted blower
meets the volume and pressure
requirements of the cabinet.
Mechanical failure of
the exhaust system
Inspect the exhaust system.
Leak or additional
‘load’ on the exhaust
system
Inspect the exhaust system
