60
Table 24 – Heating Service Troubleshooting
PROBLEM
CAUSE
REMEDY
Burners Will Not Ignite.
Misaligned spark electrodes.
Check flame ignition and sensor electrode positioning.
Adjust as needed.
No gas at main burners.
Check gas line for air, purge as necessary. After purging
gas line of air, allow gas to dissipate for at least 5 minutes
before attempting to relight unit.
Check gas valve.
Water in gas line.
Drain water and install drip leg to trap water.
No power to furnace.
Check power supply, fuses, wiring, and circuit breaker.
No 24 v power supply to control
circuit.
Check transformer. Transformers with internal overcurrent
protection require a cool down period before resetting.
Miswired or loose connections.
Check all wiring and wire nut connections.
Burned---out heat anticipator in
thermostat.
Replace thermostat.
Broken thermostat wires.
Run continuity check. Replace wires, if necessary.
Inadequate Heating.
Dirty air filter.
Clean or replace filter as necessary.
Gas input to unit too low.
Check gas pressure at manifold. Clock gas meter for input.
If too low, increase manifold pressure, or replace with
correct orifices.
Unit undersized for application.
Replace with proper unit or add additional unit.
Restricted airflow.
Clean filter, replace filter, or remove any restrictions.
Blower speed too low.
Use high speed tap, increase fan speed, or install optional
blower, as suitable for individual units.
Limit switch cycles main burners.
Check rotation of blower, thermostat heat anticipator
settings, and temperature rise of unit. Adjust as needed.
Too much outdoor air.
Adjust minimum position.
Check economizer operation.
Poor Flame
Characteristics.
Incomplete combustion (lack of
combustion air) results in:
Aldehyde odors, CO, sooting
flame, or floating flame.
Check all screws around flue outlets and burner
compartment. Tighten as necessary.
Cracked heat exchanger.
Overfired unit — reduce input, change orifices, or adjust
gas line or manifold pressure.
Check vent for restriction. Clean as necessary.
Check orifice to burner alignment.
Burners Will Not Turn
Off.
Unit is locked into Heating mode
for a one minute minimum.
Wait until mandatory one---minute time period has elapsed
or reset power to unit.
48TC
Summary of Contents for 48TC 04 Series
Page 27: ...27 COOLING CHARGING CHARTS cont C14064 Fig 33 Cooling Charging Charts 12 5 Ton 48TC...
Page 29: ...29 COOLING CHARGING CHARTS cont C13218 Fig 35 Charging Chart 48TC Size D16 48TC...
Page 40: ...40 C14052 Fig 51 Typical Smoke Detector System Wiring 48TC...
Page 122: ...122 APPENDIX III WIRING DIAGRAMS C12413 Fig 103 48TC A04 A07 Power Diagram 208 230 1 60 48TC...
Page 124: ...124 APPENDIX III WIRING DIAGRAM LIST C12415 Fig 105 48TC A04 A07 Power Diagram 575 3 60 48TC...
Page 126: ...126 APPENDIX III WIRING DIAGRAM LIST C13246 Fig 107 48TC A08 A12 Power Diagram 575 3 60 48TC...
Page 128: ...128 APPENDIX III WIRING DIAGRAM LIST C13247 Fig 109 48TC D08 D12 Power Diagram 575 3 60 48TC...
Page 130: ...130 APPENDIX III WIRING DIAGRAM LIST C13249 Fig 111 48TC D14 Power Diagram 575 3 60 48TC...
Page 139: ...139 APPENDIX III WIRING DIAGRAMS C12423 Fig 120 48TC D16 Power Diagram 575 3 60 48TC...
Page 143: ...143 APPENDIX III WIRING DIAGRAM LIST C13485 Fig 124 48TC 16 PremierLink Control Diagram 48TC...
Page 145: ...145 APPENDIX III WIRING DIAGRAM LIST C13487 Fig 126 48TC 16 RTU Open Control Diagram 48TC...
Page 146: ...146 APPENDIX III WIRING DIAGRAM LIST C14124 Fig 127 48TC D08 14 E08 14 W7220 2 Speed IFM 48TC...
