Finned copper tube gas boilers & water heaters – Boiler Manual
36
TROUBLE-SHOOTING
SYMPTOM
CHECK
ACTION
1
No Power To Unit
1. Power not connected
2. External circuit breaker open
3. Relay board fuse (24V) blown
4. Transformer circuit breaker open
(4 stage)
1. Wire unit to line voltage
2. Reset breaker
3. Replace fuse
4. Reset breaker
2
No Action On Call For Heat
1. Primary limit or other control/interlock
open
2. Low water cutoff open
3. Stage control sensor(s) not wired
or are malfunctioning
4. Stage control malfunction
1. Check indicator board, reset limit or
control or resolve problem as applicable
If not resolved, check wiring and
condition of limit.
2. Check circulating pump
2.
Check pump contact in J-box
2.
Check LWCO wiring and condition
3. Wire sensor(s) to J-box or replace as
necessary
Check error message on control, refer to
control documentation
4. Replace stage control
3
No Power To Pump
1. Pump contact not wired
2. Stage control malfunctioning
3. Pump malfunctioning
1. Wire pump contact to J-box
2. Replace stage control
3. Replace pump
4
No Power to Power Venter
1. Power venter contact not wired
2. Power venter not wired to external power
3. Relay fault
4. Power venter fault
1. Wire power venter contact to J-box
2. Wire power venter as shown in
connection diagram
3. Replace relay
4. Replace power venter
5
Power Venter On, No Action From Unit
1. Power venter interlock open
2. Power venter interlock not wired
1. Check indicator board for power vent
indication
If indication exists, check flue or chimney
for blockage
2. Wire power venter interlock as shown in
connection diagram
6
No Power To Blower(s)
1. Blower(s) not plugged in
2. Relay fault
3. Blower(s) malfunctioning
4. Fault in prepurge circuit
1. Plug in blower(s)
2. Replace blower relay
3. Replace blower(s)
4. Replace timer board
