Preferred FlexFit 110 - Fuel Selection Changed; Low Oxygen

5-98 Troubleshooting – LCD Messages
FlexFit – Linkageless Control – Revision 1.0
PREFERRED
UTILITIES MFG CORPORATION
TT
RR
OO
UU
BB
LL
EE
SS
HH
OO
OO
TT
II
NN
GG
Fuel Selection Changed Lockout
When ring on one fuel, the fuel select switch was changed to a different fuel.
Fuel Valve Closed Limit switch is on curve Lockout
The closed limit switch must be outside the curve points.
Fuel Valve Open Limit switch is on curve Lockout
The open limit switch must be outside the curve points.
High Fire/Purge Switch Hold then Lockout
The high re/purge interlock is not made when it should be.
High Flue Temperature Hold then Lockout
High ue gas temperature (terminals 147 & 148). Check for low water level in the drum or economizer. Could also be caused
by gas leakage through tangent tubes on a watertube boiler.
Ignition Position Is Not On Curve Lockout
The fuel servo ignition position must be greater than the lowest fuel position and lower than the highest fuel position.
Ignition Positions Not Veried Hold then Lockout
If the ignition output position (curve point) isn't veried, the burner will hold at ignition, waiting for the position to be veried by
the technician. The ignition position can only be veried during boiler ignition mode.
Invalid Relay Board Lockout
There is a problem with the relay board inside the FlexFit BMS. Verify eld wiring and then contact the factory.
Leak Test: Downstream Valve Leak Lockout
The downstream gas SSOV (Safety Shut Off Valve) failed the leak test. Inspect and manually test to conrm.
Leak Test: Pressure High After Venting Lockout
Indicates that the downstream gas valve is not opening.
Leak Test: Pressurizing Failed Lockout
Indicates that the downstream gas valve is not closing or has a leak; could also indicate a leak in the gas piping train.
Leak Test: Upstream Valve Leak Lockout
The upstream gas SSOV (Safety Shut Off Valve) failed the leak test. Inspect and manually test to conrm.
Low Fire Start Switch Hold then Lockout
The low re start interlock is not made when it should be.
Low Oxygen Hold then Lockout
Low oxygen was detected for more than "P2.3.7 Low O2 Lockout Delay" seconds. Check the settings of "Fuel-Air > O2 Analyzer"
on page 4-67. Possible causes: O2 sensor faulty, O2 sensor out of calibration, burner F/A ratio out of calibration, or burner
maintenance problem. A combustion technician must re-inspect the burner for proper operation.
Main Trial Flame Failure Lockout
Flame proven contact at terminal FR opened during main trial for ignition (MTFI). Check scanner sighting and ame appearance
during main fuel light-off.
Max Fuel - Fuel Point Min: Span too small Lockout
The span between the user entered "Max Fuel" and the lowest detected fuel point is too small.
Max Fuel - Min Fuel: Span too small Lockout
The span between the user entered "Min Fuel" and "Max Fuel" is too small.
Nonvolatile Storage Corruption Lockout
There is a corruption of the nonvolatile storage (likely due to power surge/brownout). Contact Preferred Instruments.
O2 A/D Error Hold then Lockout
Both parameters "P2.3.4 Low O2 Lockout Option" and "P2.3.8 Oxygen Malfunction Lockout Option" are enabled and an O
2
analyzer A/D error was detected that could cause a false O
2
reading.
O2 Calibration Data Bad Hold then Lockout
Both parameters "P2.3.4 Low O2 Lockout Option" and "P2.3.8 Oxygen Malfunction Lockout Option" are enabled and an O
2
calibration data error was detected that could cause a false O
2
reading.