Honeywell L7224A Installation Instructions Manual page 10

L7224A,C; L7248A,C,L OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT
.
Table 8. Controller Operating Sequence with External Low Limit device connected trough the ZR terminal.
Action
Zone Request (ZR) terminal is connected to
L1 (External Low Limit call for heat).
Boiler temperature exceeds the High Limit.
Zone Request input is de-energized (External
Low Limit is satisfied).
Table 9. L7224 Controller Operating Sequence with Domestic Hot Water connected trough the ZR terminal.
Action
Zone Request (ZR) terminal is connected to
L1 (Domestic Hot Water calls for heat).
Boiler temperature exceeds the High Limit.
Zone Request input is de-energized
(Domestic Hot Water is satisfied).
Aquastat
Error Code
Err1 Aquastat sensor fault; check water sensor.
Err2 ECOM fault; check EnviraCOM™ wiring.
Err3 Excessive electrical noise or frequency out of range. Hardware fault; replace controller.
Err4 B1 fault; check B1 wiring/voltage.
Err5 Low Line; check L1-L2, 110 Vac.
Warning: Fuse; check ECOM wires, replace fuse.
a
Err6
Err7 Warning: EEPROM, HL, LL, Hdf, Ldf; reset to default values.
Repeated B1 fault (voltage present at B1 when output is turned off); check B1 wiring/voltage. 25
b
Err 8
a Warning: Outdoor Reset System failure; communication to Outdoor Reset Module lost,
Err9
Outdoor Reset Module failure, multiple outdoor temperature sensors detected on the bus, or
outdoor temperature sensor failure. Check EnviraCOM wiring (1, 2, 3), check sensor wiring.
a Warning: Boost Failure; Boost Mode active at least once per cycle for the last 60 consecutive
Err 10
cycles. Check Outdoor Reset curve settings.
a DHW Module/Sensor failure; communication to DHW Module lost, DHW Module failure, or
Err 11
temperature sensor failure. Check EnviraCOM wiring (1, 2, 3), check sensor wiring.
a
Warnings are generated to enunciate the system is not operating optimally, but the Aquastat is still operating and
maintaining boiler temperature. In the instance where an Outdoor Reset Module is used, the warnings may indicate a
reset curve setting error one or more features is not running optimally, and the Aquastat is reverting to default settings
or has stopped running the Outdoor Reset algorithms. The warnings are cleared when the issue(s) is resolved.
b
To clear Err 8 condition, depress and hold all three user keys simultaneously for 60 seconds. Err 8 condition clears
and display returns to normal. Err 8 condition is designed to catch welded relays on the Aquastat and will normally
only occur near end of life for the control. If Err 8 condition has occurred early in the controls life, be sure to check for
voltage feedback to B1 when B1 should be off and check current draw on b terminal to be sure oil burner is not draw-
ing excessive current. Err 8 condition will keep repeating if B1 fault is not cleared.
System Diagnostic
Condition Condition
Boiler is cold, Display is OFF.
house is cold.
Display is ON.
68-0281—16
Boiler temperature is checked. Burner starts when water temperature
is below High Limit setting. Circulator turns off.
Burner is turned off. Burner restarts when the water temperature
drops below the High Limit setting minus the Differential.
Burner is turned off.
Boiler temperature is checked. Burner starts when water temperature
is below High Limit setting.
Burner is turned off. Burner restarts when the water temperature
drops below the High Limit setting minus the Differential.
Burner is turned off.
Table 10. LED Error Codes.
Cause/Action
Table 11. Troubleshooting Guide
Check
120 Vac System power.
24 Vac T-T
24 V present; disconnect
thermostat, short T-T.
120 Vac at B1-B2
Refer to Err on display.
10
®
CONTROLLERS
System Response
System Response
Action
Turn system power on.
No 24 V; replace control.
Boiler starts, check wiring and thermostat.
• If no, replace control.
• If yes, check burner and wiring.
—
EnviraCOM
Alarm
18
18
18, 58
64
59
92
N/A
50, 53, 149
150
146, 147,
148