White Rodgers 921 User Manual

4

TEMPERATURE

INDICATORS

TEMPERATURE

ADJUSTMENT

BUTTONS

b.  

To increase the temperature press and release the 

HOTTER button once.  The temperature indicators will 
now display the new temperature setting.  

Press and release the HOTTER button until you have 
reached the desired setting. 

WILL NOT CONTINUE TO RAISE THE SETTING. The Button 
must be pressed and released for each temperature change 
desired.  
To avoid scald injury, set the control to the lowest setting 
which will deliver your needed hot water.  Refer to 

Table 1 to 

determine the approximate temperature setting, and the ap-
proximate time for scald injury at that temperature.

3.  When you have completed setting the control wait 30 

seconds to see that the temperature indicators go off and 
the control enters “Sleep” mode. 

TURE INDICATORS WILL BE OFF DURING NORMAL 
OPERATION.  If any time you see the indicators on, there 
may be a system error and you should consult the “Trou-
bleshooting” section of this document, or contact a trained 
service professional.

If you use hot water frequently and in short spurts, water tem-
perature can occasionally exceed the temperature setting by 
up to 30°F because of the dynamics of the appliance.  Keep 
this in mind when you are selecting a temperature higher than 
the factory default setting.
Be sure to protect babies and the infirm or others with im-
paired mobility who cannot get out of the hot water quickly.  

70 (Vacation)

N/A

110
115
120

5 minutes

125
130

30 seconds

135
140

5 seconds

145
150

1.5 seconds

160

Under 1 second

Flashing

1.   The control uses an automatic ignition system to light 

the burner.  

2.   Wait at least five (5) minutes to clear out any gas, and 

then smell around the appliance area near the floor. If you 
smell gas, 

STOP!  Follow the instructions “What to do if 

you smell gas” on the first page of this instruction sheet. 
If you do not detect gas, continue with the next step.

3.  Make sure that both the inner and outer doors are in place.  

These doors are located where the burner tube enters the 
water heater at the bottom.  Both doors must be in place 
for safe operation.

4.  Turn on power to the water heater.  This can be done either 

by turning on the disconnect switch to the water heater, 
or plugging in the water heater to a nearby outlet. The in-
staller should have made this provision for you, and it must 
meet local and state ordinances or the National Electric 
Code, whichever applies.

5.  For a brief time (one to five seconds) all of the indicators 

on the front of the control should come on, and then turn 
off.  This indicates that the control has completed the self-
diagnostic test, and is ready for operation.  If any combi-
nation of indicators remain illuminated, either refer to the 
troubleshooting section of this manual, or contact a quali-
fied service person.

6.  The water heater is now ready for operation, and will 

begin to heat the water to the factory default setting of 
approximately 70°F.  If an alternate temperature setting is 
required, please refer to the following section “Temperature 
Regulation”. 

After the gas and electrical connections are made and the 
water heater tank is full of water, the control will now start to 
heat the water to the factory default setting of approximately 
70°F.  If a higher setting is desired, start with the setting at the 
triangle ( ).  This is approximately the 120°F setting, and the 
safest and most economical setting for the water heater.
To change the temperature setting for either cooler or warmer 
water, the following steps are necessary:
1.  “Wake up” the temperature indicators by pressing the 

COOLER and HOTTER temperature adjustment buttons at 
the same time and releasing after one second (see Figure 
4). One or two of the temperature indicators will light up. 
These indicators will only remain on for 30 seconds if no 
further buttons are pressed. After 30 seconds the control 
will go back to “Sleep” mode, and both buttons will again 
have to be pressed to see the water temperature setting.

2.   If this is the first time that the control has been used, the 

leftmost green indicator will be illuminated indicating the 
water temperature setting of approximately 70°F. See Table 
1 for an explanation of what each of the temperature indi-
cators mean.    

a. 

To decrease the temperature press and release the 
COOLER button once.  The temperature indicators will 
now display the new temperature setting.  Press and 
release the COOLER button until you have reached the 
desired setting.  HOLDING DOWN THE BUTTON WILL 
NOT CONTINUE TO LOWER THE SETTING.  The 
Button must be pressed and released for each tem-
perature change desired.