Honeywell L7224U Manual Del Usaurio página 11

System Condition Diagnostic Condition
Boiler is cold, Display is OFF.
house is cold.
Display is ON.
TT-LED is OFF.
Display is ON.
TT-LED is OFF.
Display is ON.
TT-LED is ON.
B1 LED is ON.
Display is ON.
TT-LED is ON.
Boiler is hot, house Display is ON.
is cold. TT-LED is ON.
C1 LED is ON.
Display is ON.
TT-LED is ON.
C1 LED is OFF.
ZC LED is ON
Display is ON.
TT-LED is ON.
ZC LED is OFF
Boiler is hot, no hot Display is ON.
potable water
a
Refer to Table 3 for Display and LED locations.
b
ZC LED ON indicates ZC terminal power is OFF.
c
ZC LED OFF indicates ZC terminal power is ON.
L7224U OIL AND ELECTRIC BOILER ELECTRONIC AQUASTAT
Table 10. Troubleshooting Guide
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.
120 Vac at C1-C2.
Boiler below the Low Limit
temperature, wait for boiler to go
above Low Limit temperature.
b
.
Boiler above LL? If yes, check for
120 Vac between ZC and L2.
c
.
Boiler Demand signal from the
water heater (either 120 Vac at ZR-
L2, or 0 Vac on T-T; depends on
installation and "duu" setting)
"Zr" reads "On" (or "tt" reads "On")
"duu" setting
Check DHW Module and DHW
Sensor
11
a
.
Check
Turn system power on.
No 24 V; replace controller.
Boiler starts, check wiring
and thermostat.
• If no, replace controller.
• If yes, check burner and
—
• 120 Vac at C1-C2, check
• Wiring ok, is pump
• If pump is running, check
—
• If no 120 Vac, replace
• If yes, check zone relays,
• 24 Vac on T-T (or 0 Vac on
• Wiring OK, check the
• "Zr" reads "OFF" but
• Set duu to ON if 120 Vac
• Set duu to OFF if
• DHW Module not properly
®
CONTROLLER
Action
wiring.
wiring to pump.
running? If not, replace
the pump.
for trapped air or closed
zone valves.
controller.
circulators and wiring.
ZR-L2), check wiring to
water heater
water heater
120Vac on ZR-L2, replace
the control
water heater demand is
connected to ZR
open/closed water heater
demand is connected to
T-T
connected and/or DHW
Sensor improperly
positioned
69-1720EFS—11