A.O. Smith cyclone BFC - 80, Installation And Service Manual

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Instruction manual BFC 74
Fan speed too low 1. Check the fan speed
2. If the fan speed is too low, check the settings
3. If the settings are correct, then replace the fan.
4. Modify the settings if incorrect
5. Reset appliance controller
Differential air pressure
switch not closing
during pre-purge
DAPS leads 1. Check the wiring between the DAPS and the controller
2. a) If any wires are damaged, the wiring harness must be
replaced.
b) Properly connect any loose wiring
3. Reset appliance controller
See the BFC electrical diagram (17 "Appendices")
To replace the necessary parts, you must contact your installation
engineer
Loose DAPS hoses 1. Check the hoses between the DAPS and the burner/fan
2. a) Replace any broken hoses.
b) Properly connect any loose hoses
3. Reset appliance controller
Heat exchanger and/or
chimney flue is blocked
1. Measure the pressure differential across the DAPS
2. Compare the pressure values
(2.4.5 "Pressure switch")
3. Check heat exchanger, condensation drainage and/or chimney
flue for blockages
4. Clear any blockage that may be present.
5. Reset appliance controller
Defective controller 1. Check that the controller is receiving power
2. Check that the controller is correctly connected
3. If there is no electrical power, check the power supply to the
terminal block, or replace the controller
4. Rectify any incorrect connections
5. Reset appliance controller
Code + Description Cause Solution Remark