A.O. Smith BTX-100 Service Handbook page 39

ULTRA HIGH EFFICIENCY POWER VENT/POWER DIRECT VENT - SERVICE MANUAL
CCB (CONT)
J7 Socket - Temperature Probe/ECO (immersion probe - top of the water heater)
PIN #
1
2
3
4
J9 Port - Communication Port - Not Used
J10 Socket - Not Used
J11 Port - Communication Port - Not Used
J13 Socket - Blower Speed Control (VFD)
PIN #
1
2
3
4
5
6
7
8
J15 Socket - Not Used
J16 Port - Communication Port - UIM Display (user interface module)
S1 Dip Switch
The S1 dip switches are configured from the factory and should not be changed. The
illustration below shows the 4 dip switches with labeling. Dip switches are toggle type micro
switches. Flipping a dip switch towards "Open" would be the same as "Off." Flipping a dip
switch the other way (towards the switch numbers) is the same as "On."
Dip switch #1 is used to configure the water heater to declare a fault condition and lock out
after one or three failed trials for ignition. The factory setting is "on" for three trials.
Dip switches #2 and #3 are used when this control system is installed on other products.
The factory setting for these two dip switches is "on."
Dip switch #4 is a spare, configuration does not matter.
OFF
OPEN
Technical Literature Department
ECO (energy cut out) 24 VAC out (red wire)
Upper temperature probe (thermistor) +5.0 VDC (black wire)
Upper temperature probe (thermistor) -5.0 VDC (black wire)
ECO (energy cut out) 24 VAC return (red wire)
Not used
Not used
To Blower low voltage PWM plug (see page 10) - pin #5 (white w/grn stripe)
Not used
Not used
Not used
To Blower low voltage PWM plug (see page 10) - pin #4 (white w/blue stripe)
To Blower low voltage PWM plug (see page 10) - pin #1 (white w/brn stripe)
1 Retry
Use Yes
Ext
Input
Type Tstat
Spare
Servicing should only be performed by a Qualified Service Agent
DESCRIPTION
DESCRIPTION
38 of 52
3
Retries
ON
No
CLOSED
Vent
Spare
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