Carrier 58DRC - Manual (Page 9)

HEATtNG & COOLING
58DRC
Counterflow Gas-Fired Furnaces
Table 6 — Trouble Analysis Chart (cont)
SYMPTOM CAUSE REMEDY
Pilot will not light
(cont) Spark shorting out to main burner Readjust electrode as specified
No gas at pilot burner Clean pilot orifice
Check voltage to terminals 3 and 5 of gas valve
Check for proper opening of pilot valve, broken
wires, or loose connections If no deficiency is
found, replace valve assembly
Burners will not ignite No 115-volt power to furnace Connect to power supply Check fuse, wiring, or
circuit breaker
No 24-volt power to control circuit Replace transformer
Miswired or loose connections Check all wiring and all wire nut connections.
No gas at main burners Check voltage to terminals 1 and 2 of gas valve
Check for proper opening of main gas valve, broken
wires, or loose connections If no deficiency is
found, replace gas valve assembly
Dirty pilot — yellow flame Clean pilot orifice
Blower operates
continuously
Thermostat fan switch in ON
position
Move thermostat fan switch to AUTO, position.
Fusible link blown Correct combustion air and venting practice —
repiace fuse link with identical part
Dirty filter causing limit operation Clean dirty air filter — reinstall.
Defective heat relay Replace printed-circuit board.
Inadequate heating Furnace undersized for application Replace with proper size furnace.
Gas input to furnace too low Check gas pressure at manifold Clock gas meter for
input If too low, increase manifold pressure or
install correct orifices
Limit switch cycles main burners Clean dirty air filter — reinstall.
Increase blower speed
Open registers — ductwork restricted.
Manual reset limit switch contacts
open Blower motor failure — replace motor.
Thermostat anticipator set too low Check thermostat circuit amps and set anticipator
accordingly. See Fig 8
Aldehyde odors, (CO),
sooting flame — floating
flame Incomplete combustion — poor
flame characteristics
Adjust air shutter on burners to provide soft, blue
flame Check all screws around flue outlets and
burner compartment Tighten
See “Location & Air for Combustion & Ventilation”
(Procedures for Gas-Fired Furnaces)
Replace cracked heat exchanger
Reduce input and check orifices — furnace
overfired
Check vent for restriction.
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Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obiigations
Book|1 |4 PC 101 Catalog No 535-843 Printed in U S A Form58DRC-1SI Pg9 7-85 Replaces: New
For repiacemenf items use Carrier Specified Parts
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