A.O. Smith cyclone BFC - 80 Installation And Service Manual page 73

Code + Description Cause
Air pressure switch fails Air pressure switch
to close during pre- leads
purge.
Loose air pressure
switch hoses
Heat exchanger and/or
chimney flue is blocked
Defective controller
Fan supplying The live (phase) wires
insufficient pressure between frequency
controller and fan are
connected wrong way
around
Instruction manual BFC
Solution
1. Check the wiring between the air pressure switch and the
controller. Rectify any defect:
- if any wires are damaged, replace the wiring harness
- properly connect loose or detached hoses
2. Reset appliance controller
1. Check hoses between air pressure switch and burner/fan.
Rectify any defect:
- if any wires are damaged, replace the wiring harness
- properly connect loose or detached hoses
2. Reset appliance controller
3. Measure the pressure differential across the air pressure switch
4. Check the values (2.4.5 "Pressure switch")
5. Check heat exchanger, condensation drainage and/or chimney
flue for blockages
6. Clear any blockage that may be present.
7. Reset appliance 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
1. Check the wiring between the fan and the freq. controller
2. Rectify the assembly if it is incorrect
3. Reset appliance controller
Remark
See the BFC electrical diagram (17 "Appendices")
To replace the necessary parts, you must contact your installation
engineer
is
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