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LP-532 REV. 8.13.2014
LP-532 REV. 8.13.2014
Error code
Meaning
Cause
Operating DHW overheating
switch
(Manual reset)
This water heater has two overheating
switches. One attached at burner
and the other at DHW outlet. These
sensors act as dual safety device in
case of DHW temperature sensor’s
malfunction.When the overheating
switch is disconnected an error code is
shown, fan continues to operate until
error code is clear.
Failure event
DHW overheating switch faulty or disconnected.
Check point
① Perform overheating switch
inspection when error appears and
burner physical temperature is not
high.
②
Check connector and if no problem,
measure resistance of the overheating
switch located at heat exchanger outlet and
replace overheating switch when the value
is 0Ω.
Chapter 4 Troubleshootion
Error code
Meaning
Cause
Air Pressure Switch open
(Manual reset)
When exhaust vent or condensate
blockages occur, error code 29 will
appear.
Failure event
In case of vent or condensate blockage, the air pressure in the combustion system exceeds the APS
setting and Er 29 is displayed.
Check point
① Check APS wiring to
ensure proper connection.
② Check APS hose (check hose damages).
③ Check condensate
discharging line.
④
If above conditions are normal:
Check APS resistance with multimeter
Check for resistance(0L)
If OL does not display replace switch
Chapter 4 Troubleshootion