The control system has detected closed contacts at the Blower Prover air pressure switch out of sequence. Blower Prover air pressure switch contacts should be open at the beginning of each heating cycle – see the Sequence of Operation on page 40.
Check all wiring between the Blower Prover air pressure switch and the CCB’s J6 Socket (page 36) pins 6 & 7. Ensure there are no shorted or pinched wires.
Ensure there are no jumper wires installed on the Blower Prover switch.
Ensure there are no jumper wires installed between the CCB’s J6 Socket pins 6 & 7.
Review the air pressure switch information beginning on page 18. Perform the pressure switch test procedure for the Blower Prover air pressure switch – see pages 21 through 23. Replace the Blower Prover switch if defective.
Call the technical support phone number shown on the water heater labeling for further assistance if the problem has not been corrected after performing the procedures outlined here.