T-M50 / T-M50 ASME Service Manual
Ver. 1.05
46
CONFIDENTIAL
Error Code
Malfunction description
Cancellation method
Miscommunication between Parent and Child
units for Easy-Link systems.
Restoring proper cable connections
between all the water heaters and the
multi-unit controller (TM-MC01). When
the computer detects proper connections
between the multi-unit controller and the
units (water heater), "761" error code will
cease to display.
Diagnosis
Checkpoint
761
1 Inspect cable connections between Parent and Child units.
2 Check for signs of power surges.
Error Code
Malfunction description
Cancellation method
Turn off the power or water supply
Imperfect combustion
(Refer to section 12-4)
If not possible, press and hold the INC
and DEC buttons on the computer board
simultaneously for more than 3 sec.
Diagnosis
Checkpoint
991
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, when the water heater has been installed indoors.
6 Check the type of vent cap, when the water heater has been installed
outdoors.
7 Check if there is any blockage in the intake air and/or exhaust.
8 Check if there is dust and lint in burner and heat exchanger, when the water
heater has been installed in laundry room.
9 Check if there is grease and dirt in burner and fan motor, when the water
heater has been installed in restaurant.
10 Check the manifold pressure in the water heater.
