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240 (T-H3J), 340 (T-H3S) and 540 (T-H3) models Service Manial
Ver. 1.00
CONFIDENTIAL
Error Code
Malfunction description
Cancellation method
941
Abnormal exhaust temperature
(Direct Vent Indoor models only)
Turn off the power or water supply
Diagnosis
Check point
1 Check how long the water heater has been installed and in use.
2 Check the vent length.
3 Check if there is any blockage in the intake air and/or exhaust.
4 Check if there is dust and lint in burner and heat exchanger, when
the water heater has been installed in laundry room.
5 Check the manifold pressure in the water heater.
6 Check if the set temperature is higher than 140˚F (60˚C) and the
system is recirculation. Recirculation system with high temperature
settings (above 140˚F) can lead to this error code.
K1
K2
Error Code
Malfunction description
Cancellation method
991
Imperfect combustion
(Refer to section 12-3)
Turn off the power or water supply
If not possible, press and hold
the INC and DEC buttons on the
computer board simultaneously for
more than 3 sec.
Diagnosis
Check point
1 Check the gas type of the water heater.
2 Check how long the water heater has been installed and in use.
3 Check the installation place.
4 Check the altitude/elevation of area of where the water heater
installed.
5 Check the vent length.
6 Check if there is any blockage in the intake air and/or exhaust.
7 Check if there is dust and lint in burner and heat exchanger, when
the water heater has been installed in laundry room.
8 Check if there is grease and dirt in burner and fan motor, when the
water heater has been installed in restaurant.
9 Check the manifold pressure in the water heater.