To increase setpoint temperature limit of the appliance,
▶ Access the menu LM - Temperature Limited (
Section 6.6) and select Unlocked.
A lower temperature set point will reduce the risk of scolding,
reduce energy consumption and increase the longevity of the
The temperature shown on the display is device measured,
always check with your hand before bathing children or elderly.
Setting the water temperature
The desired temperature of hot water can be adjusted on the
front control panel of the heater.
The water heater has an electronically controlled gas valve that
modulates the burner input in response to both varying hot
water flow rates and/or changes in any incoming and outgoing
6.4.1 Programming the default setpoint temperature
▶ Touch the symbol
▶ Hold the "OK" button for 3 seconds to save the default set
When the display stops blinking, the default set point
temperature is saved in memory.
Selecting the default setpoint temperature
In order to select the default setpoint temperature
▶ Touch the "OK" button.
Display shows the default setpoint temperature, which is now
the hot water selected setpoint-temperature.
6.4.2 Solar Mode
If the appliance does not ignite, it means that the desired set
temperature would be exceeded even running at minimum BTU.
In this condition, the solar mode indicator will show on the
In most cases, solar mode is activated if the inlet water
temperature exceeds the set point temperature minus 1 °F
Solar mode/warm inlet temperature activation formula
Temp. inlet ≥ [Temp. set - 1 °F (0.5 °C)]
Ex.: 111 °F (43.9 °C) ≥ [112 °F (44.4 °C) - 1 °F (0.5 °C)]
Greentherm T9900 SE/i – 6 720 813 635 (2019/03)
to select the desired