Manual

- 4 -
TWO COMBUSTION SECTIONS WITHIN THE 910 (T-M50)
The water heater contains two combustion sections. The section that turns on first is whichever
section the water heater decides is the primary section. The moment at which the secondary
section fires will depend on the total flow rate and set temperature of the water heater:
Flow rate at which the secondary section fires
( GPM )
Set temperature of the 910 (T-M50)
(°F)
3.2 100-120
2.9 125,130
2.6 140
2.4 145,150
2.1 155-185
Example: If the set temperature is 120ºF:
＊The section(s) in operation is indicated by the black square(s).
Right combustion section
＊The primary and secondary section will reverse roles every 100 firing cycles or every 12 hours of unit operation.
Left combustion section
o
r
910 (T-M50) 910 (T-M50) 910 (T-M50) 910 (T-M50)
Depending on which side is the primary section
Total Flow < 0.5 GPM
(no section turns on)
0.5 GPM ≦ Total Flow < 3.2
GPM
(p
rimar
y
section fires onl
y)
3.2 GPM < Total Flow
(both primary and
secondary sections fire)