Operating instructions
VENTILATOR HOOD 
14 
SYMPTOM  POSSIBLE CAUSE  SUGGESTED REMEDY 
Entire unit inoperative 
No lights glow 
No buzzer sounds 
Unit unplugged.  Plug power cord into receptacle 
Circuit breaker off or tripped  Reset circuit breaker 
Damaged power cord  Replace power cord 
Damaged power switch  Check switch. Replace as req’d. 
External interlock jumper loose or 
damaged (unit is not connected to 
building fire control system) 
Check jumper. Repair or replace 
as required 
External interlock open (unit 
connected to building fire control 
system) 
Locate and rectify open circuit 
condition in building fire control 
system. 
Cooking appliance inoperative 
“POWER” light on hood ON. Vent 
fan working ok with no service 
Contactor, wiring or connectors 
damaged 
Replace contactor 
Repair wiring 
Cooking appliance inoperative 
“POWER” light on hood ON. 
Vent fan working OK. 
"SERVICE REQUIRED" light ON  
Vacuum line to switch VS4  
restricted 
Check for restriction in vacuum 
line to switch. 
Vacuum switch VS4 open or 
defective 
Check vacuum switch VS4. 
Replace as req’d. 
Vacuum pickup port in plenum, or 
vacuum port on blower plugged 
Clean vacuum ports 
NOTE: Vacuum port in plenum 
may appear as a place to attach 
a nozzle. Do not attach a nozzle 
here. It will block the vacuum 
signal (see pg 11). 
Fire damper tripped 
Replace fire damper 
NOTE: While the fusible link alone 
may be replaced, once the 
damper has tripped it may no 
longer function reliably. 
Grease baffle and/or filter pack 
position switch(es) open 
Missing or un-seated filter assy. 
Reseat filter or adjust interlock 
switch. 
Vacuum switch VS1 open or 
damaged 
Be sure pre-filter is hooked in 
position. Check for damaged 
vacuum line, or one that is 
disconnected at the vacuum 
switch or pick-up port. Also check 
port for grease contamination. 
Vent fan working OK, but amber 
“CHECK FILTERS” light stays ON  
HOOD SECTION - TROUBLESHOOTING SUGGESTIONS 
SV504 SvcManual WV-4H(RW) 










