York 92% GF9 - User Manual

This document is a comprehensive user, maintenance, and service manual for the York International 92% GF9 / GM9 / GY9 Upflow gas furnace models. It provides essential information for safe and efficient operation, as well as detailed instructions for maintenance and troubleshooting.

Function Description

The York gas furnace is designed to provide warmth and comfort in residential and non-residential settings. It operates by burning natural gas or LP propane gas to heat air, which is then circulated throughout the building. The furnace is equipped with an automatic hot surface ignition system, eliminating the need for a pilot light. When the thermostat calls for heat, the inducer motor first purges the heat exchanger of any remaining gases. The hot surface ignitor then glows, and after a warm-up period, the gas valve opens, allowing gas to flow and ignite. Shortly after ignition, the blower motor starts, distributing warm air. Once the thermostat's set temperature is reached, the gas valve closes, the main burners turn off, and the blower continues to run until the remaining warm air is distributed, completing the heating cycle.

The furnace incorporates several safety features to ensure reliable operation. A spring-loaded safety cut-off switch automatically cuts off electrical power if the blower panel is removed. The control board includes self-diagnostic capabilities with a blinking LED to indicate fault codes, aiding in troubleshooting. These codes cover various issues, from flame sensing problems and pressure switch malfunctions to limit switch openings and reversed line voltage polarity. The control also stores up to five error codes in memory, which can be retrieved by a qualified service technician, even if power to the furnace is lost. A 60-minute automatic reset from lockout feature provides protection against temporary malfunctions, allowing the unit to restart after an hour if the issue is resolved.

The furnace also supports continuous and intermittent blower operation for cooling. In continuous blower mode, the motor operates on a speed tap wire connected to the cooling terminal on the control board. In intermittent mode, the blower operates when there is a call for cooling, with a fixed 60-second fan-off setting for SEER enhancement.

Usage Features

The manual emphasizes safe and proper usage of the furnace. Users are instructed to keep the furnace area clear of combustible materials, gasoline, and other flammable vapors and liquids. Proper airflow for combustion is crucial, so air openings on and around the furnace must not be blocked.

Starting and shutting down the furnace involves a clear sequence of steps. To start, users must set the thermostat to the lowest setting, turn off electrical power, remove the burner door, move the gas control switch to "OFF," wait five minutes to clear any gas, then move the switch to "ON," replace the burner door, turn on electrical power, and finally set the thermostat to the desired temperature. If the appliance fails to operate after three ignition trials, users are advised to follow the shutdown instructions and contact a service technician or gas supplier.

To turn off the appliance, users should set the thermostat to the lowest setting, turn off electrical power if service is to be performed, remove the upper access panel, move the gas control switch to "OFF," and replace the burner access panel. In case of overheating or gas valve failure, users are instructed to turn off the external manual gas valve in the supply line before shutting off electrical power.

The furnace is designed for use with Natural Gas and LP Propane Gas ONLY; burning any other liquid or solid fuel is strictly prohibited due to the risk of damage, fire, personal injury, and property damage.

Maintenance Features

Regular maintenance is crucial for the furnace's safe and efficient operation. The manufacturer recommends that a qualified service agency perform an annual inspection and cleaning of the entire heating portion of the unit. However, some visual inspections and filter maintenance can be performed by the user.

Key maintenance items include:

Air Filters: Dirty filters restrict airflow and can damage furnace components. Filters should be checked every three months, or weekly for new construction during the first four weeks, and every three weeks thereafter if the indoor fan runs continuously. The manual provides detailed instructions for determining the correct filter size based on cabinet width and return air duct configuration. Filters must be installed externally to the furnace casing. Throw-away filters should be replaced with new ones of the same size, while cleanable filters can be cleaned with a vacuum cleaner or garden hose and allowed to dry completely before re-installation. It is critical NOT to operate the furnace without a suitable air filter.
Blower Care: Even with good filters, blower wheels and motors can accumulate dust. The entire blower assembly should be inspected annually. Light dust can be brushed and vacuumed. If the blower cannot be properly cleaned without removal from the furnace, a qualified service agency should perform this service. A critical warning advises users NOT to move the clip-on weight on the indoor fan wheel, as it is used for balancing and moving it will cause vibration.
Motor Lubrication: The motors in these furnaces are permanently lubricated and do not require periodic oiling.
Visual Inspections: Every time filters are changed, users should visually inspect the combustion air and vent pipe for blockage or leakage, check all components for good condition and signs of deterioration, and inspect drain lines for cracks or leaks. Any dirt or lint on surfaces or components should be noted, but users should not attempt to clean them themselves; cleaning by a qualified service professional is recommended.
Professional Cleaning: The manual specifies that cleaning operations for the burner, heat exchanger, and secondary heat exchanger must be performed by a qualified service agency. This includes burner removal and cleaning, cleaning inside the heat exchanger tubes with a flexible wire brush, and vacuuming loose scale and dirt. For the secondary heat exchanger, this involves removing vent piping, drain lines, and the vent blower housing.

The manual also provides troubleshooting guidance, starting with visual checks such as verifying power, open gas shut-off valves, and secure wiring connections. Users are advised to review the sequence of operation and observe the system's response to diagnose problems. A strict warning is issued against bypassing any safety control or attempting to repair controls, emphasizing that defective controls should be replaced with UPG Source 1 Parts.