Supplement 4988-4 Page 3
The following instructions will help resolve the majority of field service problems encountered with Series 4988 Zephyr Burners. PROBLEM REMEDY I. Blower motor will not start (a) Magnetic starters tripped out. Reset starter overloads. Check motor amps and size of heater coils. (b) Fuse in disconnect blown. Replace fuse(s). Check blower motor amps. Check wiring to blower motor. (c) Motor inoperative. Repair or replace motor. (d) Flame supervision. Press reset switch. II. LOW FIRE WILL NOT IGNITE (a) Manual low fire gas valve not open. Open valve. (b) Low fire solenoid valve not opening. Check for voltage at solenoid coil. If voltage is not present, determine why. Check coil for continuity. If open, replace coil. (c) Insufficient low fire gas pressure. Low fire gas regulator outlet pressure should be 5" to 10"wc. Adjust if necessary. (d) Low fire adjusting valve closed or Open valve if closed. Remove the cap and adjust the screw for correct low fire incorrectly adjusted. fl ame.
(e) Spark plug not arcing.
Remove plug and holder from burner. Attach ignition wire and lay on burner. Shut manual gas valves and power the transformer. The spark should easily jump the plug gap. Remove plug and holder from burner. Attach ignition wire and lay on burner. Energize ignition transformer and check to see that spark is not inside spark plug holder. If spark is arcing to the plug holder, replace the wire. Remove plug wire, energize the transformer, and using an insulated screwdriver, short the high voltage terminal to ground. If the spark jumps less than ¼ ", replace transformer. Use caution, the ignition transformer delivers 6000 volts.
(f) Ignition lead shorting out.
(g) Ignition transformer inoperative.
III. Main Flame will not ignite (a) Manual gas valve is closed. (b) Automatic safety shutoff valves
Open the valve.
Check terminals at valve. If valves is powered and will not open, replace valve.
not open. (c) Low fire did not light or is unstable. Readjust low fire. See item (II) above. (d) Gas modulating motor not at low
A low fire limit switch in the motor must be made before gas shutoff valve will
position.
open.
IV.Main Flame is Long and Yellow (a) Main gas regulator outlet
Check gas pressure either at the burner gas inlet tap or at the metering orifice if so equipped. pressure set too high. Readjust regulator per step 14 of the start-up instructions if necessary. With only the circulating fan and the burner blower on, reset the inlet damper to give a 1"wc air pressure differential between the burner and duct as per step 5 of the start-up instructions. Open disconnect switch at starter and switch any two motor lead wires. Remove motor and impeller as a unit and clean. Do not remove the impeller from the motor shaft for cleaning.
(b) Air inlet damper incorrectly set.
(c) Blower running backwards.
(d) Blower impeller dirty.
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