Honeywell L7248A,C,L LED Error Codes Aquastat EnviraCOM, Cause/Action Alarm, Check Action

L7224A,C; L7248A,C,L OIL ELECTRONIC AQUASTAT® CONTROLLERS

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Table 8. Controller Operating Sequence with External Low Limit device connected trough the ZR terminal.

Action	System Response
Zone Request (ZR) terminal is connected to	Boiler temperature is checked. Burner starts when water temperature
L1 (External Low Limit call for heat).	is below High Limit setting. Circulator turns off.
Boiler temperature exceeds the High Limit.	Burner is turned off. Burner restarts when the water temperature
	drops below the High Limit setting minus the Differential.

Zone Request input is de-energized (External Burner is turned off.

Low Limit is satisfied).

Table 9. L7224 Controller Operating Sequence with Domestic Hot Water connected trough the ZR terminal.

Action	System Response
Zone Request (ZR) terminal is connected to	Boiler temperature is checked. Burner starts when water temperature
L1 (Domestic Hot Water calls for heat).	is below High Limit setting.
Boiler temperature exceeds the High Limit.	Burner is turned off. Burner restarts when the water temperature
	drops below the High Limit setting minus the Differential.
Zone Request input is de-energized	Burner is turned off.
(Domestic Hot Water is satisfied).

Table 10. LED Error Codes.

Aquastat		EnviraCOM
Error Code	Cause/Action	Alarm
Err1	Aquastat sensor fault; check water sensor.	18
Err2	ECOM fault; check EnviraCOM™ wiring.	18
Err3	Excessive electrical noise or frequency out of range. Hardware fault; replace controller.	18, 58
Err4	B1 fault; check B1 wiring/voltage.	64
Err5	Low Line; check L1-L2, 110 Vac.	59
Err6a	Warning: Fuse; check ECOM wires, replace fuse.	92
Err7	Warning: EEPROM, HL, LL, Hdf, Ldf; reset to default values.	N/A
Err 8b	Repeated B1 fault (voltage present at B1 when output is turned off); check B1 wiring/voltage.	25
Err9a	Warning: Outdoor Reset System failure; communication to Outdoor Reset Module lost,	50, 53, 149
	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.
Err 10a	Warning: Boost Failure; Boost Mode active at least once per cycle for the last 60 consecutive	150
	cycles. Check Outdoor Reset curve settings.
Err 11a	DHW Module/Sensor failure; communication to DHW Module lost, DHW Module failure, or	146, 147,
	temperature sensor failure. Check EnviraCOM wiring (1, 2, 3), check sensor wiring.	148

aWarnings 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.

bTo 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.

Table 11. Troubleshooting Guide

System	Diagnostic
Condition	Condition	Check	Action
Boiler is cold,	Display is OFF.	120 Vac System power.	Turn system power on.
house is cold.
	Display is ON.	24 Vac T-T	No 24 V; replace control.
		24 V present; disconnect	Boiler starts, check wiring and thermostat.
		thermostat, short T-T.
		120 Vac at B1-B2	• If no, replace control.
			• If yes, check burner and wiring.
		Refer to Err on display.	—

68-0281EFS—05 10