electronic gas valve heat settings that are labled A,B,C,D .
when you want to set to any of the heat temp settings,the red knob arrow po
inter needs to right on either of these heat settings .... but the key is..
. only having knob pointed directly on the letter,if your red knob is off c
enter of marker your water heater will not work ,you will get a flash code
and will lockout .youc can reset gas valve by unpluging powered 24volt tran
sformer damper which contols all electronics.then plug back in. being sure
to power switch off then on also. and foremost heat setting knob is lined u
p with any of the letters A,B,C,D.
I learned this by
trial and error...