XIX. MAINTENANCE
WARNING
HIGH VOLTAGE!
TO AVOID PERSONAL INJURY OR DEATH DUE TO ELECTRICAL SHOCK, DISCONNECT ELECTRICAL POWER BEFORE PERFORMING ANY MAINTENANCE. IF YOU MUST HANDLE THE IGNITER, HANDLE WITH CARE. TOUCHING THE IGNITER ELEMENT WITH BARE FINGERS, ROUGH HANDLING OR VIBRATION COULD DAMAGE THE IGNITER RESULTING IN PREMATURE FAILURE. ONLY A QUALIFIED SERVICER SHOULD EVER HANDLE THE IGNITER.
ANNUAL INSPECTION
The furnace should be inspected by a qualified installer, or service agency at least once per year. This check should be performed at the beginning of the heating season. This will ensure that all furnace com- ponents are in proper working order and that the heating system func- tions appropriately. Pay particular attention to the following items. Re- pair or service as necessary.
•Flue pipe system. Check for blockage and/or leakage. Check the outside termination and the connections at and internal to the furnace.
•Heat exchanger. Check for corrosion and/or buildup within the heat exchanger passageways.
•Burners. Check for proper ignition, burner flame, and flame sense.
•Drainage system. Check for blockage and/or leakage. Check hose connections at and internal to furnace.
•Wiring. Check electrical connections for tightness and/or corrosion. Check wires for damage.
•Filters.
FILTERS
CAUTION
TO ENSURE PROPER UNIT PERFORMANCE, ADHERE TO THE FILTER SIZES GIVEN IN THE RECOMMENDED MINIMUM FILTER SIZE TABLE OR SPECIFICATION SHEET APPLICABLE TO YOUR MODEL*
*NOTE: Please contact your distributor or our website for the applicable Specification Sheet referred to in this manual.
MAINTENANCE
Improper filter maintenance is the most common cause of inad- equate heating or cooling performance. Filters should be cleaned (permanent) or replaced (disposable) every two months or as re- quired. When replacing a filter, it must be replaced with a filter of the same type and size.
FILTER REMOVAL
Depending on the installation, differing filter arrangements can be applied. Filters can be installed in either the central return register or a side panel external filter rack (upflow only). A media air filter or electronic air cleaner can be used as an alternate filter. Follow the filter sizes given in the Recommended Minimum Filter size table to ensure proper unit performance.
To remove filters from an external filter rack in an upright upflow instal- lation, follow the directions provided with external filter rack kit.
HORIZONTAL UNIT FILTER REMOVAL
Filters in horizontal installations are located in the central return regis- ter or the ductwork near the furnace.
To remove:
1.Turn OFF electrical power to furnace.
2.Remove filter(s) from the central return register or ductwork.
3.Replace filter(s) by reversing the procedure for removal.
4.Turn ON electrical power to furnace.
MEDIA AIR FILTER OR ELECTRONIC AIR CLEANER REMOVAL
Follow the manufacturer’s directions for service.
BURNERS
Visually inspect the burner flames periodically during the heating sea- son. Turn on the furnace at the thermostat and allow several minutes for flames to stabilize, since any dislodged dust will alter the flames normal appearance. Flames should be stable, quiet, soft, and blue (dust may cause orange tips but they must not be yellow). They should extend directly outward from the burners without curling, floating, or lifting off. Flames must not impinge on the sides of the heat exchanger firing tubes.
INDUCED DRAFT AND CIRCULATOR BLOWERS
The bearings in the induced draft blower and circulator blower motors are permanently lubricated by the manufacturer. No further lubrication is required. Check motor windings for accumulation of dust which may cause overheating. Clean as necessary.
CONDENSATE TRAP AND DRAIN SYSTEM (QUALIFIED SERVICER ONLY)
Annually inspect the drain tubes, drain trap, and
FLAME SENSOR (QUALIFIED SERVICER ONLY)
Under some conditions, the fuel or air supply can create a nearly invisible coating on the flame sensor. This coating acts as an insulator causing a drop in the flame sense signal. If the flame sense signal drops too low the furnace will not sense flame and will lock out. The flame sensor should be carefully cleaned by a qualified servicer using emery cloth or steel wool. Following clean- ing, the flame sense signal should be 1 to 6 microamps at 115 volts.
IGNITER (QUALIFIED SERVICER ONLY)
If the igniter and the surrounding air are at about 70°F and the igniter wires are not connected to any other electrical components, the resistance of the igniter should not exceed 75 ohms. If it does, the igniter should be replaced.
FLUE PASSAGES (QUALIFIED SERVICER ONLY)
The heat exchanger flue passageways should be inspected at the beginning of each heating season. If necessary, clean the pas- sageways as outlined below.
1.Turn OFF the electrical power and gas supply to the furnace.
2.Disconnect the gas line and remove the burner/ manifold assembly by removing the screws securing the assembly to the partition panel.
3.Disconnect the flue pipe system from the induced draft blower.
4.Remove the induced draft blower and, drain and pressure tap hoses from the recuperator coil front cover.
5.Remove the recuperator coil front cover to expose the coil tubes and turbulators.
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