Schwank 2-Stage Series - Manual (Page 36)

36
SET(U)-F / ITT(U)-F Manual
IM091221
RD: FEB 2014
RL: 8B
21. TROUBLESHOOTING GUIDE - FENWAL DSI
(also see Heater Troubleshooting next page)
SYMPTOM RECOMMENDED ACTION(S)
1. Dead
A. Miswired - check electrical supply (120Vac ± 5%)
B. Transformer bad (24Vac ± 10%)
C. Fuse/Circuit breaker bad
D. Bad control (check LED for steady on)
2. Thermostat on
- no blower output
A. Miswired
B. Bad thermostat no voltage @ terminal W
C. Bad control (check LED for steady on)
3. Pressure switch input okay,
but no Trial-for-Ignition af-
ter purge delay
A. Miswired (check PSW terminal voltage: 24Vac ± 10%)
B. Flame sense problem (existing flame: check LED - 2
flashes)
C. Bad control (check line voltage between L1 & IND)
4. Valve on, no spark
A. Shorted electrode
B. Open HV cable
C. Bad control
5. Spark on, no valve
A. Valve coil open
B. Open valve wire
C. Bad control (check 24Vac voltage between V1 & V2)
6. Flame ok during TFI, no flame sense (after TFI)
A. Bad electrode
B. Bad HV igniter wire
C. Poor ground at burner
D. Poor flame (check flame current)