Grimsby Furnace Manual

The Grimsby Furnace is a high-efficiency residential heating system with advanced temperature control, multiple heating stages, integrated blower system, digital thermostat compatibility, safety shutoff features, energy-saving modes, and easy maintenance access. Powered by natural gas or propane with 120V AC electrical requirements. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

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

Features at a Glance

Key components: Heat exchanger, blower assembly, gas valve, control board, ignition system, pressure switches, filter compartment, thermostat connections.

Feature	Description
Multi-stage heating	Two-stage operation for efficiency and comfort
Variable speed blower	Quiet operation with optimized airflow
Digital control board	Microprocessor-based control system
Hot surface ignition	Reliable electronic ignition system
Filter access door	Easy filter replacement
Safety shutoff switches	Multiple safety interlocks
Diagnostic LED	Error code display for troubleshooting
Gas valve	Precise fuel control
Drain connections	Condensate removal system
Thermostat terminals	Standard 24V thermostat connections

Installation

Unpack and inspect contents. Position in designated location.

Gas connection: Use approved gas piping; pressure test for leaks.
Vent system: Install proper vent piping per local codes.
Electrical: Connect 120V AC power with proper grounding.
Thermostat: Connect compatible digital thermostat.
Drain line: Install condensate drain per instructions.

WARNING! Installation must be performed by qualified technician. Ensure proper clearances and ventilation.

First-Time Setup

Power on furnace; follow startup sequence.

System check: Control board performs self-diagnostic test.
Gas pressure: Verify correct manifold pressure settings.
Airflow: Check blower operation and airflow settings.
Thermostat programming: Set desired temperature schedules.
Test operation: Run through complete heating cycle.

CAUTION! Ensure gas supply is off during initial electrical connections.

Specifications

Heating Capacity: 40,000-120,000 BTU/h range
Efficiency: Up to 96% AFUE
Stages: Two-stage heating operation
Blower: Variable speed ECM motor
Fuel Type: Natural gas or propane
Electrical: 120V AC, 60Hz
Venting: PVC pipe compatible
Sound Level: Ultra-quiet operation
Warranty: 10-year heat exchanger, 5-year parts

Controls and Settings

Access settings via thermostat or control board dip switches.

Thermostat Controls: Temperature setpoint, fan operation, system mode, schedule programming.

Control Board: LED diagnostic codes, blower speed settings, heating stages, timing adjustments. DIP switches for blower delays, heating stages, accessory configurations.

Connecting Thermostat

Compatible with most 24V digital thermostats.

Turn off power to furnace before wiring.
Connect R (power), W (heat), G (fan), C (common) terminals.
For advanced thermostats: Connect Y (cooling) if applicable.
Program thermostat per manufacturer instructions.

Tip: Use proper thermostat wire gauge and ensure secure connections.

Operating Modes

Multiple operating modes for efficiency and comfort.

Heating mode: Primary heating operation with stage control.
Fan only: Continuous or intermittent blower operation.
Standby: System ready for heat demand.
Lockout: Safety shutdown with diagnostic code.
Test mode: Service diagnostic operation.

WARNING! Do not attempt to override safety lockout conditions.

Safety Features

Flame rollout switches, high limit switches, pressure switches, ignition safety lockout, condensate overflow switch. All safety devices must be properly connected for operation.

Maintenance & Cleaning

Annual professional maintenance recommended. Monthly filter inspection/replacement. Keep area around furnace clear.

CAUTION! Turn off power and gas supply before any maintenance. Use only manufacturer-approved parts.

Regulatory Information

UL certified for safety standards. ANSI Z21.47 compliance for gas appliances. Meets DOE efficiency requirements. For support, visit www.grimsbyfurnace.com or contact 1-800-555-HEAT. Manufactured under license by Grimsby Heating Systems.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No heat	Thermostat/Power/Gas	Check thermostat setting; verify power and gas supply; check filter.
Blower not running	Motor/Control	Check blower door switch; verify control board output.
Frequent cycling	Filter/Airflow	Replace dirty filter; check for blocked vents.
Lockout condition	Safety device	Check diagnostic LED; reset power; call for service if recurring.
Unusual noises	Mechanical issues	Check for loose components; blower wheel condition.

Reset: Power cycle furnace to clear temporary lockouts.

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