Amana Furnace AMS80 Service Manual

The Amana AMS80 is a high-efficiency gas furnace designed for residential heating applications. This service manual provides comprehensive information for HVAC technicians including installation procedures, troubleshooting guides, maintenance requirements, and technical specifications for proper servicing and repair of the AMS80 series furnace.

1. Safety Precautions 2. Technical Specifications 3. Installation Procedures 4. Electrical Connections 5. Gas Line Connections 6. Venting Requirements 7. Start-Up Procedures 8. Control Board Operation 9. Maintenance Schedule 10. Troubleshooting Guide 11. Error Code Diagnostics

Safety Precautions

Before servicing the AMS80 furnace, observe all safety precautions to prevent personal injury and equipment damage.

Hazard	Precaution
Electrical Shock	Disconnect power before servicing; verify with voltage tester
Gas Leaks	Use leak detection solution; never use open flame
Carbon Monoxide	Ensure proper venting; test with CO detector
Hot Surfaces	Allow furnace to cool before handling components
Moving Parts	Disconnect power before accessing blower assembly

Technical Specifications

Model Series: AMS80
Input BTU/H: 40,000 - 120,000
AFUE Rating: 80%
Gas Type: Natural Gas (LP conversion kit available)
Electrical: 120V AC, 60Hz
Motor Type: PSC Blower Motor
Heat Exchanger: Clam shell type, aluminized steel
Dimensions: Varies by model (check specific model label)
Venting: Category I, PVC or metal vent approved

Installation Procedures

Proper installation is critical for safe and efficient operation.

Location Selection: Install in dry, clean area with adequate combustion air and service clearance.
Combustion Air: Ensure adequate fresh air supply per local codes.
Clearances: Maintain minimum clearances to combustible materials as specified.
Leveling: Ensure furnace is level for proper condensate drainage.
Ductwork: Connect supply and return ducts securely with proper sealing.

WARNING! Installation must comply with all local codes and manufacturer specifications.

Electrical Connections

Follow NEC and local electrical codes for all wiring.

Disconnect Power: Turn off power at service panel before beginning.
Line Voltage: Connect 120V supply to furnace junction box.
Low Voltage: Connect thermostat wires to control board terminals (R, W, G, C).
Grounding: Ensure proper equipment grounding.
Polarity: Maintain correct hot and neutral connections.

CAUTION! Incorrect wiring can damage control board and create safety hazards.

Gas Line Connections

Gas piping must be sized and installed according to local codes.

Pipe Sizing: Use adequate pipe diameter for BTU input and length.
Shut-off Valve: Install manual gas valve within 6 feet of furnace.
Drip Leg: Include sediment trap before gas valve.
Pressure Test: Test for leaks at maximum operating pressure.
Manifold Pressure: Adjust to specifications on rating plate.

WARNING! Use approved pipe thread compound and test thoroughly for leaks.

Venting Requirements

Proper venting is essential for safe operation and efficiency.

Vent Type	Requirements
PVC	Schedule 40 PVC, minimum 2" diameter
Metal	Type B vent, properly supported and sealed
Clearances	Maintain required clearances to combustibles
Termination	Proper roof/wall termination per code
Slope	1/4" per foot back toward furnace

Start-Up Procedures

Follow this sequence for proper furnace commissioning.

Verify all connections are secure and proper.
Open gas supply valve slowly.
Restore electrical power.
Set thermostat to heat mode above room temperature.
Observe ignition sequence and flame characteristics.
Check temperature rise and adjust blower speed if necessary.
Verify proper vent operation and draft.
Complete combustion analysis and adjust as needed.

Control Board Operation

The integrated furnace control manages all system functions.

LED Status Light: Flashing patterns indicate system status and error codes.

Terminals: R (24V hot), W (heat), G (fan), C (common), Y (cooling optional)

Sequence of Operation: Call for heat → Inducer motor on → Pressure switch close → Hot surface igniter on → Gas valve open → Flame sense → Blower on after delay

Maintenance Schedule

Regular maintenance ensures optimal performance and longevity.

Monthly: Check air filter; replace if dirty
Annual: Professional inspection and cleaning
Every 2 Years: Heat exchanger inspection
As Needed: Blower motor lubrication (if applicable)
Seasonal: Check vent system for obstructions

Tip: Keep maintenance records for warranty compliance.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No heat	Thermostat, power, gas supply	Check thermostat setting, circuit breaker, gas valve position
Blower not running	Motor, capacitor, control board	Test motor windings, check capacitor, verify control signal
Furnace short cycling	Dirty filter, limit switch	Replace filter, check air flow, test limit switch operation
No ignition	Igniter, gas valve, pressure switch	Test igniter continuity, verify gas pressure, check pressure switch
Lockout condition	Flame sense, vent blockage	Clean flame sensor, check venting for obstructions

Error Code Diagnostics

The control board LED provides diagnostic information through flash patterns.

Flash Pattern	Description	Resolution
1 Flash	Pressure switch stuck open	Check inducer, venting, pressure switch tubing
2 Flashes	Pressure switch stuck closed	Replace pressure switch
3 Flashes	Limit circuit lockout	Check airflow, filter, blower operation
4 Flashes	Ignition failure	Check gas supply, igniter, flame sensor
5 Flashes	Flame loss after establishment	Clean flame sensor, check grounding

Reset Procedure: Power cycle furnace to clear lockout conditions.

Technical Support: 1-888-292-6262; www.amana-hac.com