Robertshaw 9420 - Manual (Page 7)

7
NOTE: ONCE THE THERMOSTAT TURNS OFF, A BUILT IN 5-MINUTE
DELAY PREVENTS THE SYSTEM FROM TURNING ON AGAIN.
THIS PROTECTS THE COMPRESSOR. NO ADDITIONAL TIME
DELAY RELAY IS REQUIRED. TO OVERRIDE THE 5-MINUTE DELAY
FOR INSTALLATION, PRESS THE RESET BUTTON.
3. Put the EMER-HEAT-OFF-COOL switch into
the OFF position. The air conditioning system
should turn off. The display will read SYSTEM OFF.
4. Put the EMER-HEAT-OFF-COOL switch into
the HEAT position. The display will read HEAT.
5. Press the ٙ button until the temperature
setting is at least 3 degrees above room
temperature. The heating system should
turn on. The fan may not turn on immediately,
depending on the fan delay built into the furnace.
The flame icon

will be displayed
( 1 st stage heating;  2 nd stage heating).
6. Put the EMER-HEAT-OFF-COOL switch into
the OFF position. The heating system should
turn off. The fan may continue to run for a
short period of time. The display will read
SYSTEM OFF.
7. Put the -ON-AUTO switch into the ON
position. The blower fan should turn on.
The display will show a
and ON.
8. Put the -ON-AUTO switch into the AUTO
position. The blower fan should turn off.