Furnace Manual Fan Switch

The furnace manual fan switch is a critical component that allows manual control of the furnace blower fan independently of the heating cycle. This switch enables homeowners to run the fan continuously for improved air circulation or to manually activate the fan for specific maintenance purposes. Below are key sections covering features, installation, operation, troubleshooting, and safety considerations.

1. Features at a Glance 2. Installation 3. Operation 4. Specifications 5. Controls and Settings 6. Wiring Connections 7. Maintenance 8. Safety Features 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Manual fan switch, wiring terminals, mounting bracket, ON/OFF positions, integrated safety features.

Feature	Description
Manual Operation	Direct control of furnace blower fan
ON Position	Activates blower fan continuously
OFF Position	Returns fan to automatic thermostat control
Wiring Terminals	Standard screw terminals for easy connection
Mounting Bracket	Easy installation on furnace or wall
Safety Lockout	Prevents simultaneous heating and manual fan operation
LED Indicator	Visual confirmation of fan activation
Weather-resistant	Suitable for furnace room environments
Universal Compatibility	Works with most standard furnace systems
Manual Override	Bypasses thermostat for direct fan control

Installation

Proper installation ensures safe and reliable operation. Follow these steps carefully.

Turn off power: Shut off electricity to furnace at circuit breaker.
Locate mounting position: Choose accessible location near furnace control panel.
Mount switch: Secure bracket using provided screws.
Wire connections: Connect to furnace control board per wiring diagram.
Test operation: Restore power and test switch functionality.

WARNING! Always disconnect power before installation. Improper wiring can cause equipment damage or fire hazard.

Operation

Understanding proper switch operation ensures optimal performance.

Automatic Mode: Switch in OFF position - fan operates per thermostat settings.
Manual Mode: Switch in ON position - fan runs continuously for air circulation.
Transition: Switching between modes requires 30-second delay for motor protection.
Indicator Light: LED illuminates when fan is manually activated.

CAUTION! Do not switch rapidly between positions. Allow fan to complete cycle before changing settings.

Specifications

Voltage Rating: 120V AC, 60Hz
Current Capacity: 15A maximum
Switch Type: Single pole, single throw (SPST)
Terminal Type: Screw terminals, 14-18 AWG wire
Operating Temp: -20°C to 60°C (-4°F to 140°F)
Mounting: Surface mount with included bracket
Dimensions: 3.5" x 2.25" x 1.5"
Color: Standard white finish
Warranty: 1-year limited warranty

Controls and Settings

Simple two-position control with integrated safety features.

Switch Positions: ON (manual fan operation), OFF (automatic thermostat control)

Operation: Turn switch to ON for continuous fan operation. Return to OFF to restore automatic thermostat control. LED indicator provides visual confirmation of manual operation status. Built-in delay prevents rapid cycling for motor protection.

Wiring Connections

Proper wiring ensures safe operation and compatibility with furnace system.

Power Off: Ensure furnace power is disconnected at breaker.
Identify Terminals: Locate G (fan) terminal on furnace control board.
Connect Wires: Run 18-2 thermostat wire from switch to control board.
Secure Connections: Tighten screw terminals to specified torque.
Verify Wiring: Double-check connections against wiring diagram.

Tip: Use wire nuts for secure connections and electrical tape for insulation.

Maintenance

Regular maintenance ensures long-term reliability.

Monthly: Test switch operation and LED indicator.
Quarterly: Inspect wiring for damage or loose connections.
Annually: Clean switch contacts with electrical contact cleaner.
As Needed: Tighten terminal screws to maintain secure connections.

WARNING! Always disconnect power before performing any maintenance.

Safety Features

Built-in safety mechanisms protect equipment and users.

Thermal Protection: Automatic shutoff if overheating detected. Electrical Isolation: Prevents backfeed to control board. Delay Timer: 30-second minimum between mode changes. Lockout Protection: Prevents simultaneous heating and manual fan operation.

Care & Cleaning

Proper care maintains switch performance and longevity.

Unplug before cleaning. Use dry cloth only; no liquids or chemical cleaners. Periodically check for dust accumulation and clean with compressed air. Ensure ventilation openings remain unobstructed.

CAUTION! Do not use water or cleaning solutions. Keep away from moisture and extreme temperatures.

Regulatory Information

UL Listed: Complies with UL Standard 508. CSA Certified: Meets Canadian Standards Association requirements. FCC Part 15: Class B digital device compliant. Manufactured to ISO 9001 quality standards. For technical support, contact 1-800-555-HEAT or visit www.furnacecomponents.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Fan not running	Power loss/switch position	Check circuit breaker; verify switch in ON position.
LED not illuminated	Bulb failure/wiring	Check wiring connections; replace if LED defective.
Switch feels loose	Mounting/wear	Tighten mounting screws; inspect for mechanical wear.
Intermittent operation	Loose connections	Check and tighten all wire terminals.
Fan runs but no heat	Normal operation	Manual mode operates fan only; switch to OFF for heating.

Reset: Turn switch OFF, wait 30 seconds, then turn ON.

Service: 1-800-555-HEAT; www.furnacecomponents.com