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Finned copper tube gas boilers & water heaters – Boiler Manual
36
F
F
No Power To Unit
Power not connected
Wire unit to line voltage
External circuit breaker open
Reset breaker
Relay board fuse (24V) blown
Replace fuse
Transformer circuit breaker open (4 stage)
Reset breaker
No Action On Call For Heat
Primary limit or other control/interlock
• Check indicator board, reset limit or control or
open
resolve problem as applicable
• If not resolved, check wiring and condition of
limit.
Low water cutoff open
• Check circulating pump
• Check pump contact in J-box
• Check LWCO wiring and condition
Stage control sensor(s) not wired or are
• Wire sensor(s) to J-box or replace as necessary
malfunctioning
• Check error message on control, refer to
control
documentation
Stage control malfunction
Replace stage control
No Power To Pump
Pump contact not wired
Wire pump contact to J-box
Stage control malfunctioning
Replace stage control
Pump malfunctioning
Replace pump
No Power to Power Venter
Power venter contact not wired
Wire power venter contact to J-box
Power venter not wired to external power
Wire power venter as shown in connection
diagram
Relay fault
Replace relay
Power venter fault
Replace power venter
Power Venter On,
Power venter interlock open
• Check indicator board for power vent indication
No Action From Unit
• If indication exists, check fl ue or chimney for
blockage
Power venter interlock not wired
Wire power venter interlock as shown in
connection
diagram
No Power To Blower(s)
Blower(s) not plugged in
Plug in blower(s)
Relay fault
Replace blower relay
Blower(s) malfunctioning
Replace blower(s)
Fault in prepurge circuit
Replace timer board
Unit Does Not Spark
Incorrect spark gap or shorted ignitor lead
Adjust ignitor rod or correct short
Bad ground on fl ame sense module
Check ground connections, adjust as necessary
Low air (blocked fl ue/inlet) condition
• Check indicator board for low air indication
• If condition exists, check inlet, fl ue, chimney for
blockage
• Check combustion air/ventilation opening in
space
• Check inlet air fi lter, clean/replace as necessary
as
necessary
Spark generator fault
• Check spark generator wiring
PROBLEM
POSSIBLE CAUSES
CORRECTIVE ACTION
TROUBLE-SHOOTING
