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Part number 550-100-029/0810
GAS-FIRED WATER BOILER SERIES 1 & 2 —
Control supplement & Service guide
Troubleshooting (continued)
Instructions in this supplement are based
on factory default parameter settings.
SOFT LOCKOUT [Display flashes 9, then b in first position; last two digits on steady (code)]
Code Reason for soft lockout
Corrective actions (pressing RESET should restart boiler immediately)
Electrical shock hazard. Turn off power to boiler when working with
wiring or replacing any boiler component.
18 High limit operation — burner off
until outlet water temp drops below
203 °F minus the ON differential
1
This should only happen when the heat demand is lower than the lowest firing rate of
the boiler, such as operation of a single, small zone. Check system for:
2
Verify boiler and system are full of water
3
Make sure system does not have trapped air preventing proper flow
4
Inspect and verify system piping and components (including pipe size and circulator
capacity)
5
Verify piping agrees with boiler manual recommendations.
6
Verify proper circulator(s) operation
7
Possible loose connector on boiler outlet sensor. Tighten connector
8
Possible bad boiler supply outlet sensor
19 Return water temperature higher
than 203 °F. — burner off until
return water temp drops below
203 °F minus the ON differential
1
Verify proper direction of water flow through boiler
2
Verify boiler and system are full of water
3
Make sure system does not have trapped air preventing proper flow
4
Inspect and verify system piping and components
5
Verify piping agrees with boiler manual recommendations.
6
Verify proper circulator(s) operation
7
Possible loose connector on boiler outlet sensor. Tighten connector
8
Possible bad boiler supply outlet sensor
24 Return temp higher than supply
temp — Burner off waiting for
supply temp to rise above return
temp
1
Verify proper direction of water flow through boiler
2
Verify boiler and system are full of water
3
Make sure system does not have trapped air preventing proper flow
4
Inspect and verify system piping and components
5
Verify piping agrees with boiler manual recommendations.
6
Verify proper circulator(s) operation
7
Possible loose connector on boiler outlet sensor. Tighten connector
8
Possible bad boiler supply outlet sensor
Troubleshooting procedures — when display shows soft lockout code&IGURE
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