Cambridge Air Solutions
30
SA-Series Technical Manual
Problem
Possible Cause
Corrective Action
I. No Blower Operation
(Continued)
14. Belts
a) Belt Slipping
b) Belt broken or missing
a) Tighten belts.
b) Replace belts
II. BLOWER RUNS;
NO HEAT;
FLAME SAFETY
RELAY DOESN’T
LOCK OUT
1. Mode Selector Switch (CE-Smart
TM
)
a) Switch in VENT position
b) Defective Switch
a) Place switch in HEAT position
b) Replace switch
2. Burner Service Switch
a) Switch in OFF position
b) Defective switch
a) Place switch in REMOTE position
b) Replace switch
3. Multi-Functional PC Board
a) No input voltage on Terminal W (RCS)
b) Inlet temperature above EAT setpoint
c) Improper wiring
d) Defective board
a) Check voltage in RCS
b) Adjust EAT setpoint
c) Check wiring
d) Replace multi-functional PC board
4. Airflow Switch
a) Blower running backwards (SA350)
b) Belts slipping (SA350)
c) Blocked intake or discharge
d) Clogged airflow tubing or pickup ports
e) Defective switch
a) Reverse motor direction (SA350)
b) Tighten and/or replace belts (SA350)
c) Find and remove obstruction
d) Clean or replace tubing or pickup ports
e) Replace switch
5. Flame Safeguard Relay
a) No input voltage
b) Defective FSR
a) Check wiring
b) Replace FSR
III. BLOWER RUNS;
NO HEAT;
FLAME SAFETY
RELAY LOCKS OUT
1. Igniter
a) No current (open igniter)
b) No voltage
During trial for ignition:
a) Check igniter current
b) Check FSR output to igniter
2. High Limit
a) High limit tripped
a) See Problem Number VI (page 32)
3. Gas Valve
a) No input voltage
b) Gas valve does not open
c) Defective solenoid
a1) Check FSR output to R1 relay
during ignition trial
a2) Check gas valve circuit and wiring
b1) Compare supply to nameplate voltage
b2) Clean and/or replace gas valve parts
c) Replace solenoid or valve assembly
4. Modulating Valve
a) Minimum fire set too low
a) Adjust minimum fire on modulating valve
5. Multi-Functional PC Board
a) Low fire start set too low
b) Thermistor open or not connected
a) Adjust modulating valve voltage between
10 and 13 Volts DC
b) Properly install or replace thermistor
6. Combination Valve
a) Clogged vent orifice
b) No supply pressure
c) Improper manifold pressure
d) Defective regulator
a) Clean or replace orifice
b) Check all gas cocks and piping
c) Adjust regulator
d) Replace regulator
7. Burner
a) Defective burner
a) Replace burner
TROUBLESHOOTING INSTRUCTIONS
TROUBLESHOOTING GUIDE
