Controls, Start-Up, Operation, Service and ... - Climayoreo

Table 73 — Gas Heating Service Analysis
PROBLEM CAUSE REMEDY
Burners Will Not Ignite. Active alarm. Check active alarms using ComfortLink scrolling
marquee.
No power to unit. Check power supply, fuses, wiring, and circuit breakers.
No power to IGC (Integrated Gas Control). Check fuses and plugs.
Heaters off due to time guard to prevent short
cycling.
Check using ComfortLink scrolling marquee.
Thermostat or occupancy schedule set point not
calling for Cooling.
Check using ComfortLink scrolling marquee.
No gas at main burners. Check gas line for air and purge as necessary. After purging
gas line of air, allow gas to dissipate for at least 5 minutes
before attempting to re-light unit.
Water in gas line. Drain water and install drip.
Inadequate Heating. Dirty air filters. Replace air filters.
Gas input too low. Check gas pressure at manifold. Refer to gas valve adjustment
in Installation, Start-up, and Service Manual.
Thermostat or occupancy schedule set point only
calling for W1.
Allow time for W2 to energize.
Unit undersized for load. Decrease load or increase of size of unit.
Restricted airflow. Remove restriction.
Too much outdoor air. Check economizer position and configuration. Adjust minimum
position using ComfortLink scrolling marquee.
Limit switch cycles main burners. Check rotation of blower, thermostat heat anticipator settings,
and temperature rise of unit. Adjust as needed.
Poor Flame Characteristics. Incomplete combustion (lack of combustion air)
results in: Aldehyde odors, CO, sooting flame, or
floating flame.
Table 74 — Electric Heat Service Analysis
94
Check all screws around flue outlets and burner compartment.
Tighten as necessary.
Cracked heat exchanger, replace.
Unit is over-fired, reduce input. 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 in Minimum on-time. Check using ComfortLink scrolling marquee.
Unit running in Service Test Mode. Check using ComfortLink scrolling marquee.
PROBLEM CAUSE REMEDY
No Heat. Power failure. Call power company.
Fuse blown or circuit breaker tripped. Check CB1,
CB2, and CB3.
Replace fuse or reset circuit breaker.
Thermostat occupancy schedule set point not calling
for Heating.
Check using ComfortLink scrolling marquee.
No 24 vac at primary contactor. Check transformer and circuit breaker.
No power (high voltage) to L2 of primary contactor. Check safety switches “one-shot” backup and auto limit.
Bad electrical elements. Power off unit and remove high voltage wires. Check resistance
of heater, replace if open.