Install Instructions
Default Settings for 50D50U-843
match S8610U Default Settings
SENSE terminal on 50D50U-843
Spade Spark
Terminal on
50D50U-843
Vent Damper
Connector on
50D50U-843
50D50U-843 11-pin harness assembly
VENT DAMPER ERROR (AFTER 60 SECONDS)
STANDBY,
NOT
POWERED
CALL FOR HEAT
RECEIVED FROM
THERMOSTAT
MODULE
RECEIVES POWER,
RUNS SELF CHECK
DAMPER
CONNECTED?
DAMPER
FUSE OPENS
UPON FIRST
HEAT CALL
DAMPER
OPEN?
5 MINUTE RETRY DELAY
SPARK OFF
IF CONFIGURED, BEGIN
PREPURGE
TRIAL FOR
IGNITION
SPARK
ON
OPEN PILOT
GAS VALVE
FLAME
PROVED?
CLOSE
PILOT
VALVE
CLOSE MAIN GAS
VALVE AND PILOT
GAS VALVE
FLAME
LOST?
CALL FOR
HEAT ENDS?
RUN
OPEN MAIN
GAS VALVE
SPARK
OFF
CLOSE VENT DAMPER CLOSE MAIN GAS VALVE AND PILOT GAS VALVE
YES
NO
YES
NO
NO
YES
YES
NO
NO
YES
Existing Control Being Replaced
MV
MV/PV
PV
GND
24V
(GND)
24V
TH-W
CONFIGURABLE
When replacing Honeywell S8610U – Intermittent Pilot (IP)
Wires from 50D50U-843
11-pin harness
Factory unit wires removed
from replaced control
Other Setup Notes:
• Keep vent damper jumper plug installed on 50D50U-843 if replaced control has it installed
• When installing 50D50U-843 with this setup, leave 24V terminal on 50D50U-843 unconnected and
insulated (control will receive power from TH-W)
• To use control with a vent damper, remove vent damper jumper plug and connect damper harness assembly
to vent damper connector on 50D50U-843
• Once 50D50U-843 receives power with a vent damper connected, an internal circuit will open (non-reversible;
control with the jumper plug will no longer work)
• If there is no TH-W terminal on the replaced control, connect the wire from 24V or 25V (2) terminal on old
control to TH-W on new 50D50U-843 and leave 24V on 50D50U-843 unconnected and insulated
• For systems with air proving switch (APS), connect output of APS to TH-W on 50D50U-843
• If default settings are not being used on replaced S8610U, match correct settings to 50D50U-843 through
White-Rodgers Connect App or 7-segment Conguration Menu
• Follow all safety guidelines on page 1 and directions under MOUNTING AND WIRING DIAGRAM on page 4
Sequence of operation when 50D50U-843 is congured to replace S8610U:
MV
MV/PV COM
PV
BRN GND
24V
PSW
24V COM
TH-W
C/GND
R
5