20
RT-SVF25C-EN
Sequence of Operation
Drain Pan Condensate Overflow Switch
(Optional)
The Condensate Overflow Switch (COF) is utilized to
prevent water overflow from the drain pan. The float
switch is installed on the corner lip of the drain pan. When
the condensate level reaches the trip point, the COF relay
energizes and opens the 24VAC control circuit which
disables the unit. Once the 24VAC control circuit is opened,
a delay timer will prevent unit start-up for three minutes.
Table 22.
Ignition module diagnostics
Steady light
Module is powered up, but no active call for
heat.
Blinking at
continuous steady
rate
Active call for heat.
One blink
Loss of communication.
Two blinks
System lockout (failure to ignite, no spark,
low/no gas pressure, etc.)
Three blinks
Pressure switch (no vent air flow, bad CBM,
closed at initial call for heat). Auto reset.
Four blinks
High limit (excessive heat in combustion
chamber, low airflow). Auto reset.
Five blinks
Flame sensed and gas valve not energized
or flame sensed and no call for heat.
Six blinks
Flame rollout (CBM failure, incorrect gas
pressure, incorrect primary air). Requires
manual reset of the switch.
Seven blinks
W1& W2 swapped (electromechanical 3-10
tons units).
