42
Page
Display
Green
LED
Malfunction
descrip
tion
Diagnosis
031
One Time
Incorrect DIPswitch
se
tting
•
Check the DIPswitch se
ttings
on the PCB (Part #701).
101
Five Times Warning for the
“991” error code
•
Check if the gas type of the micro-boiler matches
the gas supplied to it.
•
Check if there is any blockage in the intake air and/
or exhaust.
•
If the micro-boiler is installed as a direct-vent
system, check whether there is enough distance
between the intake air terminal and the exhaust
terminal.
•
Check the
altitude
/eleva
tion
of area of where the
micro-boiler is installed and match the appropriate
DIPswitches.
•
Check if there is grease and/or dirt in the burner (Part
#101) and the fan motor (Part #103), especially if the
micro-boiler has been installed in a contaminated area.
•
Check if the DIPswitches match gas type of the
micro-boiler.
•
Check the manifold pressure at Max. and Min.
•
Check combus
tion
chamber tube (Part #117) to make
sure it is clear and securely installed.
111
Three Times
Ignition
failure
•
Check if the Hi-limit switch (Part #411) is properly
functioning
.
•
Check for connec
tion/b
reakage of wires (Part #412, 707,
708, 709 710), burn marks on the computer board (Part
#701), and/or soot on the
fl
ame rod (Part #108).
•
Check if there is a buzzing spark
ignition
sound
coming from the burner (Part #101) when
micro-boiler prepares for combus
tion.
•
Listen for the double “clunk” sound coming from gas
valve assembly (Part #102) when the micro-boiler
goes into combus
tion
.
•
Check if there is leaking from heat exchanger (Part #401).
•
Check that the gas is turned on.
•
Check gas supply.
121
Three Times Loss of
flame
•
Check if the Hi-limit switch (Part #411) is properly
functioning
.
•
Check for c
onnection/b
reakage of wires (Part #412,
707, 708, 710), burn marks on the computer board
(Part #701), and/or soot on the
flame
rod (Part
#108).
•
Check if there is leaking from heat exchanger (Part #401).
•
Check gas supply.
311
Two Times Outlet thermistor
failure
•
Check for connec
tion/b
reakage of wires and/or
debris on thermistor (Part #407, 408, 715).
•
Check the resistance.
321
Two Times Inlet thermistor
failure
341
Two Times Exhaust thermistor
failure
Owner's Guide
-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the micro-boiler and/or on the temperature
controller, please check the follo
wing. After checking,
c
onsult
with
the
manuf
actu
rer
.
Summary of Contents for HS120CON-LP
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