Ruud Achiever 90 Plus Furnace Manual

The Ruud Achiever 90 Plus is a high-efficiency gas furnace with AFUE ratings up to 90%, featuring a multi-speed blower motor, electronic ignition system, durable heat exchanger, quiet operation, and compatibility with various thermostat systems. Designed for residential heating applications with safety features including flame rollout protection, limit switches, and pressure switches. Below are key sections for safety, features, installation, operation, maintenance, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Thermostat 7. Operating Instructions 8. Maintenance Procedures 9. Care & Cleaning 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Multi-speed blower motor, electronic ignition system, aluminized steel heat exchanger, inducer motor assembly, gas valve, control board, filter compartment, and pressure switches.

Feature	Description
AFUE Rating	Up to 90% Annual Fuel Utilization Efficiency
Blower Motor	Multi-speed ECM for efficient airflow
Ignition System	Electronic hot surface ignition
Heat Exchanger	Aluminized steel construction
Gas Valve	Modulating for precise gas flow control
Control Board	Integrated furnace control with diagnostic LEDs
Filter System	Standard 1-inch or 4-inch media filter compatible
Venting	PVC pipe compatible for sidewall or roof venting
Safety Features	Flame rollout switches, pressure switches, limit controls
Sound Level	Quiet operation with insulated cabinet

Installation

Unpack and inspect all components. Ensure proper location with adequate clearance.

Position furnace: Place on level surface with minimum clearances as specified.
Connect gas supply: Use approved gas piping with sediment trap.
Install venting: Use PVC pipe for combustion air and flue gas.
Electrical connections: Connect 120V power supply and thermostat wiring.
Ductwork: Connect supply and return ducts securely.

WARNING! Installation must be performed by qualified HVAC technician. Gas connections require leak testing.

First-Time Setup

Power on furnace; verify proper operation through startup sequence.

Gas pressure check: Verify inlet and manifold gas pressures.
Blower speed settings: Adjust for proper airflow and temperature rise.
Thermostat configuration: Set for single-stage or multi-stage operation.
Safety checks: Verify all safety switches and controls function properly.
Combustion analysis: Check flue gas temperatures and CO levels.

CAUTION! Initial startup must be performed by qualified technician. Ensure proper ventilation.

Specifications

AFUE Rating: Up to 90%
Input BTU/H: 40,000 to 120,000 (varies by model)
Gas Type: Natural Gas or LP (with conversion kit)
Electrical: 120V, 60Hz, 1 Phase
Blower Motor: Multi-speed ECM
Venting: PVC, CPVC, or ABS (2" or 3")
Filter Size: 16x25x1 standard or 16x25x4 media
Sound Level: As low as 65 dBA
Warranty: Limited lifetime heat exchanger, 5 years parts

Controls and Settings

Access control board via front panel. Integrated diagnostic LED for troubleshooting.

Control Board: POWER switch, diagnostic LED, dip switches for configuration.

Blower Settings: Adjust blower speeds for heating mode. Gas Valve: Pressure adjustment screws. Limit Controls: Auto-reset high limit protection. Thermostat Connections: R, W, G, Y, C terminals. Diagnostic Codes: LED flash patterns indicate specific error conditions.

Connecting Thermostat

Standard 5-wire thermostat connection: R (24V), W (Heat), G (Fan), Y (Cool), C (Common).

Turn off power to furnace before wiring.
Strip thermostat wires 1/4 inch.
Connect to appropriate terminals on control board.
Secure connections and replace access panel.
Restore power and test operation.

Tip: Use compatible programmable thermostat for optimal efficiency.

Operating Instructions

Normal heating operation controlled by thermostat.

Set thermostat to desired temperature.
Furnace initiates startup sequence: inducer motor, pressure switch verification.
Hot surface igniter activates, gas valve opens.
Flame sensor confirms ignition, main blower activates after heat exchanger warm-up.
Cycle completes when thermostat satisfied.
For continuous fan operation, set thermostat to "FAN ON" position.

WARNING! Do not attempt to manually override safety controls. Contact professional for service.

Maintenance Procedures

Regular maintenance ensures optimal performance and efficiency.

Monthly: Check and replace air filter as needed.
Annual: Professional inspection and cleaning.
Blower compartment: Clean annually, lubricate if required.
Heat exchanger: Visual inspection for cracks or damage.
Vent system: Check for obstructions or damage.
Burners: Clean and verify proper flame pattern.

Care & Cleaning

Turn off power before any cleaning. Use soft brush and vacuum for internal components.

CAUTION! Do not use water or liquid cleaners. Keep electrical components dry.

Regulatory Information

ANSI Z21.47: Certified for natural gas and propane operation. UL listed. Complies with U.S. Department of Energy efficiency standards. Manufactured to meet or exceed industry safety standards. For technical support, contact Ruud at 1-800-722-2102 or visit www.ruud.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
Furnace won't start	Power, thermostat, door switch	Check circuit breaker, thermostat setting, door switch engagement.
No heat	Gas supply, ignition	Verify gas valve on, check for ignition failure codes.
Short cycling	Filter, limit switch	Replace dirty filter, check for restricted airflow.
Blower not running	Motor, capacitor, control	Check for power to blower, motor capacitor, control board signals.
Error codes flashing	Various system faults	Count LED flashes and refer to diagnostic chart in manual.

Reset: Turn power off for 30 seconds, then restore.

Service: 1-800-722-2102; www.ruud.com