Carrier Weathermaker 8000 mid-efficiency
58WAV upflow series 100


Problem: flame cut-out in a continuing cycle, with duration of burner on time decreasing with each successive loss of flame


: no lock-out, cycle continuous
: code 31 after each burner out, LED returns to solid condition when ignition sequence restarts
: cycle stops with manual end of heat call at thermostat or power off to furnace
: normal ignition sequence and timing from inducer on, to blower on, for first three cycles
: burner on time, 8 minutes first cycle, 1 minute 2nd cycle, 15 seconds 3rd cycle at which point inducer stops and blower continues for 90 seconds (after each cycle)
: 4th cycle- flame out before blower starts, after ignition sequence
: 5th cycle - burner remains lit for 1 minute 15 seconds after ignition and blower on
: 6th cycle- flame out before blower starts, after ignition sequence
: 7th cycle- flame out before blower starts, after ignition sequence
: 8th cycle- same
: 9th cycle- same
: 10th cycle- same


: each time the burner flame stops, the inducer stops with it, and the blower will continue for 90 seconds before the ignition sequence re-starts.
: from troubleshooting of two furnace technicians, pressure switch, control board, and flame sensor have been replaced
: I have installed a new Honeywell thermostat and thermostat wiring


: code 31 sates that:31 PRESSURE, DRAFT SAFEGUARD, AUXILIARY-LIMIT (when used), OR
BLOCKED VENT SHUTOFF (when used) SWITCH DID NOT CLOSE OR
REOPENED - If open longer than five minutes, inducer shuts off for 15 minutes
Before retry. Check for:
- Proper vent sizing and condensate pitch or sag.
- Inadequate Combustion air supply.
- Low inducer voltage.
- Vent restriction or high winds.
- Disconnected or obstructed pressure tubing.
- Defective inducer motor or start capacitor.
- Defective pressure switch or connections. If it opens after trial for ignition period,
blower will come on for 90 second recycle delay.


: new board- CES0110057-02, replaces CES0110057-00, updates include 'furnace will recycle if pressure switch opens and re-closes during a call for heat'

: please help