Troubleshooting Heating (Cooling/Electric Heater Models) - Heat Controller BG-81G Service Manual

Service Manual
PROBLEM
Compressor Overload inoperative. Opens too
attempts to soon.
start, or runs
Compressor attempts to start
for short
before system pressures are
periods only.
equalized.
Cycles on Low or fluctuating voltage.
overload.
8.4 Troubleshooting Heating
PROBLEM P
Fan Heater relay or contactor coil open.
Operates –
heating
Heater relay or contactor stuck
element does
open, pitted or burned.
not come on.
High limit control open.
Open thermal fuse.
Open or shorted element.
Loose connections.
Heating Restricted filter.
inadequate.
Cycling high limit control.
Exhaust or fresh air door open.
Fan operates Fan relay contacts open.
in "Constant"
speed, but
not in "Auto"
Inoperative system switch.
Loose connection.
Long "off" Heat anticipator (resistor)
and "on" shorted.
cycles.
Defective temperature sensor.
Room Air Conditioner with R-410A
POSSIBLE CAUSE
OSSIBLE CAUSE
32
TO CORRECT
Check operation of unit. Replace overload if
system operation is satisfactory.
Allow a minimum of 2 minutes for pressures
to equalize before attempting to restart.
Check voltage with unit operating. Check for
other appliances on circuit. Air conditioner
should be on separate circuit for proper
voltage, and be fused separately.
(Cooling/Electric Heater Models)
TO CORRECT
Check continuity of coil. Inspect, test
continuity with ohmmeter.
Check continuity – if open, replace.
Check continuity. Check reason for failure.
Check voltage across heater terminals.
Check amperage draw of heater.
Tighten all terminals.
Clean as recommended in Owner's Manual.
Control is set to open at 155°F± 5°F (68.3°C
+/- 15°C) and close at 130°F± 8°F (54.4°C +/-
13°C). If cycling prematurely, replace control.
Check position of fresh air door control slide.
Adjust cable if door does not close properly.
Check continuity of fan relay.
NOTE: Some models have fan relay energized
during heating cycle while others do not.
Check connections on system switch and
fan relay.
Check connections on system switch and
fan relay.
Disconnect power to unit. Remove resistor
from thermostat bulb block. Plug in unit and
allow to operate. Feel resistor for heat. If no
heat is felt, replace resistor.
Replace temp. sensor and check operation.
Heat Controller, Inc.