T-H3 Installation Manual

55 Page
-Fault Analysis of Error Codes-
If the error code is displayed on the computer board of the water heater or remote controller and/or
temperature controller, please check the following. After checking, consult with the manufacturer.
Troubleshoong
Owner's Guide
Controller
Green
LED
Malfunction
description
Diagnosis
031
One
Flash
Incorrect DIP switch
setting
 Check the DIP switch settings on the PCB (Part #701).
101
Five
Flashes
Warning for the “991”
error code
 Check the gas type of the water heater.
 Check if there is any blockage in the intake air and/or exhaust.
 If the water heater 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/elevation of area of where the water heater
is installed.
 Check if there is grease and/or dirt in the burner (Part #101) and the
fan motor (Part #103), especially if the water heater has been installed
in a contaminated area.
111
Three
Flashes
Ignition failure  Check if the Hi-limit switch (Part #412) is properly functioning.
 Check for connection/breakage of wires (Part #413, 708, 709, 711)
burn marks on the computer board (Part #701), and/or soot on the
flame rod (Part #108).
 Check if there is a buzzing spark ignition sound coming from the
burner (Part #101) when water heater prepares for combustion.
 Listen for the double “clunk” sound coming from gas valve
assembly (Part #102) when water heater goes into combustion.
 Check if there is leaking from heat exchanger (Part #401).
121
Three
Flashes
Loss of flame  Check if the Hi-limit switch (Part #412) is functioning properly.
 Check for connection/breakage of wires (Part #413, 708, 709,
711) 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).
311
Two
Flashes
Outlet thermistor
failure (240 /340 models
only)
Heat exchanger
thermistor failure
(540 model only)
 Check for connection/breakage of wires and/or debris on therm-
istor (Part #407, 408, 411, 715).
321
Two
Flashes
Inlet thermistor fail-
ure
Error code Green LED
on on on on
on on
off off off off off
321
Unit #1
PARENT
Unit #2
CHILD
Unit #3
CHILD
Unit #4
CHILD
Green LED on the computer board
Outdoor model installation
Indicator on the remote controller of Parent unit (If it is installed): “321” and "2" will alternately flash
on the display.
No. 2 Unit: The green
LED on the computer
board will indicate this
code with two flashes
every 1/2 second.
No. 3&4 Unit: No sign.