Bradford White EF-100T-399-3X - Manual (Page 11)

If normally closed pressure switch contacts open during burner operation, gas valve closes, burner shuts off. Blower
restarts after 30 seconds and runs 5 minutes to wait for pressure switch to close. If not, locks out.
The system will go into lock out mode for the following reasons:
- Pressure switches stuck open or closed.
a) Check for exhaust or intake obstructions.
b) Check for compliance with vent tables.
c) Check for evidence of moisture or condensate present in pressure switch tubing or pressure switch.
- No ignition after 3 attempts.
a) Check gas pressures.
b) Igniter resistance too high (lower resistance preferred <150 Ohms).
c) Check venturi screw adjustment (6 ½ turns from bottom)
d) Flame sense micro amp not present (1 to 5 micro amps required).
Lock out reset is accomplished by shutting OFF the line voltage to the system or opening the 24V thermostat
circuit for at least 2 seconds.
System will automatically reset lockout after 1 hour of continuous call for heat from the thermostat. Three ignition trials will
be attempted each hour until the thermostat is satisfied.
For models prior to CF serial numbers
Ignition Module Specifications
- Ignition & heating functions in response to thermostat.
- Hot surface ignition using a microprocessor to control timing, flame sensing using flame rectification & ignition
retries.
- Monitoring of system pressure switches and limit switches.
- Control of gas valve, inducer motor, and hot surface igniter element based on thermostat demand and status of
safety inputs.
- Diagnostic indicators to provide information on power to control and control status.
- Non-interchangeable polarized plug-in connectors for all interconnections.
Control Functions:
- Thermostat call for heat.
- Limit Switch Circuit (normally closed)
- Pressure Switch Circuit (normally open)
- Flame sensing.
- Low voltage supply.
- Line voltage supply.
Control Inputs: Control Outputs:
Lockout Conditions
- Inducer motor
- Hot surface igniter
- Gas valve
- Status indicator LEDs
Power - Green
Purge - Red
Igniter - Red
Valve - Red
Flame - Red
WIRING DIAGRAM
IGNITION MODULE
For models prior to CF serial numbers
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