Lochinvar FTxl 500 Service Manual page 40

3
Troubleshooting
Table 3-3 Troubleshooting Chart - Noisy System
FAULT
- Supply
pressures should be between 4 inches
w.c. and 14 inches w.c. LP gas pressures
should be between 8 inches w.c. and 14
inches w.c.
- Gas/air mixture problem.
Noisy
Operation
- Dirty/damaged burner.
- Low water flow through the heat exchanger. • Refer to Section 6 - Hydronic Piping of the
- Air in the piping system.
- Low system water pressure.
No Pump
- Blown fuse.
Operation -
Boiler Pump
System Pump
or
DHW Pump
- Faulty pump.
- Internal fault on control board.
- System pressure exceeds relief valve
setting.
Relief Valve
Opening
- Failed external relay.
No Pump
- Line voltage shut off.
Operation
- Faulty pump.
- DHW
Recirculation - Faulty DHW recirculation sensor.
Pump
- Fault in connection board.
- Fault in control board.
40
CAUSE
gas problem. Natural
Service Manual
CORRECTIVE ACTION
gas • Refer to Section 7 - Gas Connections of the
FTXL Installation and Operation Manual for detailed
information concerning the gas supply.
• Refer to the Gas Valve Adjustment Procedure on
page 49 of this manual for the proper gas valve setting.
Verify that the vent/air intake lengths do not exceed the
maximum listed in the General Venting section of the
FTXL Installation and Operation Manual.
• Refer to page 34 in this manual for the burner removal
and inspection procedure. Clean or replace the burner
as necessary.
FTXL Installation
minimum flow rates. Verify that the boiler and
system pump are running on a call for heat.
• Properly purge all air from the piping system.
• Verify system pressure is a minimum of 12 psi.
• Replace fuse F1 on the control board, see page 37 of
this manual.
Note: Make sure pump amperage does not exceed
1.8 amps.
• Replace pump.
• Replace main control board.
• Lower the system pressure below the 30 psi rating of
the supplied relief valve or replace the standard relief
valve with a higher rated valve up to the maximum
pressure of the heat exchanger.
• Improperly sized expansion tank.
• Check function of external relay.
• Check line voltage to external relay.
• Check recirculation pump.
• Check DHW recirculation sensor.
• Check low voltage connection board.
• Replace control board.
and Operation Manual for