INSTALLATION AND OPERATION INSTRUCTIONS
5-8
SL 30-175, SL 45-260 MODULATING GAS BOILERS
SYMPTOM
DIAGNOSIS
REMEDY
HI LIMIT ERROR
LCD Screen Message:
Error – Water High-Limit/LWCO
Water temperature exceeds hi-
limit or water level is low. Boiler
in hard lockout. Will reset in 1
hour. Consult service technician.
If equipped with a Low
Water Cut Off, check
for illuminated red
light on LWCO Control
Module.
Red light on
Water level oK - check manual reset water high
limit:
a) Check for any evidence of actual excess
temperature
b) Check temperature sensors
c) Check for flow problems
d) Push reset button on manual reset water high
limit (cycle power off and back on after pushing
manual reset water high limit button.
Red light off
Water level low:
a) Check air vent at top of boiler to ensure it is
working and boiler is not air locked
b) Check lCd screen for correct water pressure
c) Open water feed point (boiler fill valve or
boiler pressurization unit) to make sure system
is filled to operating pressure.
If the boiler loop is filled but the red light does
not come on, check for power at LWCO control
module (24 Vac between terminals 1 (yellow) and
3 (blue)). Check operation of LWCO per Section
5.2.7; replace LWCO control module as required.
TEMPERATURE SENSOR
ERROR
LCD Screen Message:
Error - Max. In-Out Temp.
Exceed. -> Check water flow
Water temperature signal
not within acceptable range.
Potential flow or sensor failure.
Consult service technician.
Current outlet
temperature exceeds
operating limit.
•
Check water flow.
Defective or
disconnected
temperature sensor.
•
Check wiring to temperature sensor and
control module.
•
Check temperature sensor. see
Section
5.2.1
.
MISCELLANEOUS
LCD Screen Message :
Blank – screen dark, but fan
running Indicative of power-
surge damage to appliance
•
Check transformer; replace if damaged.
•
Check circuit board for visible damage.
Summary of Contents for SL 30-175
Page 76: ...NOTES...
