Suburban NT 30 Furnace Manual

The Suburban NT 30 is a high-efficiency furnace designed for RV and mobile home applications, featuring 30,000 BTU heating capacity, direct spark ignition, electronic temperature control, multi-position installation capability, built-in safety controls, and compatibility with 12V DC power systems. 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 to Power 7. Operation 8. Maintenance 9. Safety Features 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: Burner assembly, heat exchanger, blower motor, control board, gas valve, thermostat, exhaust system.

Feature	Description
Heating Capacity	30,000 BTU/hour output
Ignition System	Direct spark ignition
Power Requirements	12V DC, 4.5 amps
Gas Type	Natural gas or propane
Installation	Multi-position (floor, wall, ceiling)
Airflow	Variable speed blower
Safety Controls	Flame rollout switch, limit switch
Exhaust	Sealed combustion system
Dimensions	14" x 10" x 7"
Weight	18 lbs

Installation

Unpack and inspect contents. Ensure proper clearances and ventilation.

Select location: Minimum 6" clearance from combustible materials.
Mount furnace: Secure with provided hardware in desired position.
Connect gas line: Use approved gas piping and fittings.
Connect ductwork: Attach supply and return air ducts.
Connect electrical: Wire to 12V DC power source and thermostat.
Install venting: Connect exhaust and intake pipes per code.

WARNING! Installation must be performed by qualified technician. Follow all local codes.

First-Time Setup

After installation, perform initial startup procedure.

Check gas connections: Test for leaks with soap solution.
Verify electrical: Ensure proper 12V DC power supply.
Set thermostat: Install batteries and set to desired temperature.
Purge gas line: Open gas valve and purge air from line.
Test ignition: Turn on furnace and verify proper startup sequence.
Adjust airflow: Set blower speed for optimal performance.

CAUTION! Never bypass safety controls. Test carbon monoxide detector.

Specifications

Model: NT 30
BTU Output: 30,000 BTU/hour
Efficiency: 85% AFUE
Gas Pressure: 11" WC natural gas, 14" WC propane
Electrical: 12V DC, 4.5 amps
Airflow: 120 CFM maximum
Sound Level: 65 dB maximum
Vent Size: 2" diameter
Warranty: 5 years heat exchanger, 1 year parts

Controls and Settings

Thermostat controls: Temperature setting, fan mode, system on/off.

Furnace Controls: Power switch, gas valve, control board LED indicators, blower speed settings.

Temperature Range: 50°F to 90°F. Fan Settings: Auto, On, Circulate. LED Codes: Green (normal operation), Red (fault condition). Gas Pressure: Factory set, adjustable by technician. Blower Speed: High, Medium, Low settings.

Connecting to Power

12V DC power connection requirements and procedures.

Turn off all power sources before connecting.
Connect positive (red) wire to 12V DC positive terminal.
Connect negative (black) wire to ground.
Connect thermostat wires to control board terminals.
Verify polarity and secure all connections.

Tip: Use proper gauge wire and fuse protection as specified.

Operation

Normal operating sequence and user controls.

Set thermostat to desired temperature above room temperature.
Furnace initiates startup sequence: blower pre-purge.
Ignition system activates: spark igniter and gas valve open.
Flame sensor confirms ignition: main burner operation begins.
Blower activates after heat exchanger warms up.
When thermostat satisfied: gas valve closes, blower continues cool-down.

WARNING! Do not operate without proper ventilation. Monitor for unusual sounds or odors.

Maintenance

Regular maintenance schedule and procedures.

Monthly: Check air filter, clean if necessary.
Seasonal: Inspect burner assembly, clean flame sensor.
Annual: Professional inspection of heat exchanger, gas pressure, vent system.
As needed: Clean blower wheel and housing.

CAUTION! Turn off power and gas supply before performing maintenance.

Safety Features

Built-in safety systems and their functions.

Safety Feature	Function
Flame Rollout Switch	Shuts off gas if flame escapes burner area
High Limit Switch	Prevents overheating of heat exchanger
Pressure Switch	Ensures proper venting before ignition
Flame Sensor	Confirms burner ignition within trial period
Thermal Fuse	Protects against electrical overload

Regulatory Information

ANSI Z21.44: Certified for recreational vehicle use. CSA 4.96: Approved for mobile home installation. UL 307A: Listed for combustible construction. For technical support, contact Suburban Manufacturing at 1-800-782-8771 or visit www.suburbanmanufacturing.com.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No heat	Power, thermostat, gas supply	Check 12V power, thermostat setting, gas valve position
Furnace short cycles	Dirty filter, blocked vent	Replace air filter, check vent pipes for obstruction
Blower runs continuously	Thermostat setting, limit switch	Check thermostat fan setting, test limit switch
Ignition failure	Gas supply, spark electrode	Verify gas pressure, clean spark electrode
Unusual odors	Dust buildup, combustion issues	Clean burners, check for proper combustion air

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

Service: 1-800-782-8771; www.suburbanmanufacturing.com