Granby B*C-3 sections, Инструкция по установке, эксплуатации и обслуживанию

Страница: 23 / 32

22
TROUBLE SHOOTING THE HONEYWELL L7248 AQUASTAT
When attempting to diagnose system performance, reference to the LED display can help to
identify specific areas not working properly. The LED display will scroll ERR, followed by a
digit (1-8). Refer to the information inside the cover of the control L7248.
Error Codes
Err 1 Sensor fault Check sensor
Err 2 ECOM fault Check Optional EnviraCOM wiring
Err 3 Hardware fault Replace control
Err 4 B1 fault Check B1 wiring/voltage
Err 5 Low line Check L1 - L2 > 110 V a/c
Err 6 Fuse Check ECOM wires, replace fuse
Err 7 EEPROM Reset limit values
Err 8 Multiple Err 4 Press/Hold I for 60 sec min*
System
Condition
Diagnostic
Condition
Check Action
Boiler is cold,
house is cold. Display is OFF 120 V a/c System power. Turn system power on
Display is ON 24 V a/c T-T No 24 V; replace control
24V present; disconnect
thermostat, short T-T
Boiler starts, check wiring and thermostat.
120 V a/c at B1-B2 . If no, replace control.
. If yes, check burner and wiring.
Boiler is not,
house is cold. Display is ON. 120 V a/c at C1-C2 . 120 V a/c at C1-C2, check wiring to
pump. Wiring OK, is pump running ?
. If not, replace the pump.
. If pump is running, check for trapped air
or closed zone valves.
TESTING SAFETY AND CONTROL DEVICES
In the event the boiler is equipped with a low water cut off, the cut off should be tested in
accordance with the manufacturer’s recommendations. When no instructions are available
follow the guidelines in ASME CSD-1 or perform the following procedures:
•
Set room thermostat at least 10°F above room tempe rature.
•
With burner operating, drain boiler slowly until the burner shuts off. This shut off should
occur when the water level falls below the low water cut off probe.
•
Check to be sure the burner shut off is not due to an open limit or flame safety issue.
•
Reset the room thermostat to the desired temperature and refill the boiler