Lennox G61MPV Furnace Installation Manual

The Lennox G61MPV is a high-efficiency, two-stage gas furnace featuring variable-speed blower technology, electronic ignition, and advanced diagnostic capabilities. This multi-position furnace is designed for residential installation with AFUE ratings up to 96.2%. Below are key sections for safety, specifications, installation procedures, wiring, startup, and troubleshooting.

Features at a Glance

Key components: Two-stage gas valve, variable-speed ECM blower motor, hot surface ignitor, pressure switches, flame sensor, integrated control board.

Safety Precautions

Critical safety information for proper installation and operation.

1. Disconnect electrical power before servicing or installing.
2. Verify gas type matches furnace rating plate (natural gas only).
3. Install carbon monoxide detectors in living areas.
4. Ensure proper combustion air supply and venting.
5. Follow all local codes and manufacturer specifications.

WARNING! Failure to follow safety procedures may result in fire, explosion, property damage, personal injury, or death. Gas furnaces must be installed by qualified technicians only.

Specifications

• Models: G61MPV-36C-090, G61MPV-36C-110, G61MPV-48C-110, G61MPV-48C-135
• Input Capacity: 66,000 to 135,000 BTU/hr
• AFUE: Up to 96.2%
• Stages: Two-stage gas valve
• Blower Type: Variable-speed ECM
• Electrical: 115V/60Hz/1Ph
• Gas Connection: 1/2" NPT
• Vent Sizes: 2" or 3" PVC/CPVC
• Operating Temp Range: -40°F to 130°F

Installation Requirements

Site preparation and clearance requirements.

1. Level, solid foundation capable of supporting furnace weight.
2. Minimum clearances: 0" sides, 1" front, 0" top (upflow), 1" bottom.
3. Adequate combustion air supply per local codes.
4. Proper drainage for condensate removal.
5. Access for service and filter changes.

CAUTION! Ensure installation location provides adequate clearance for service access and proper airflow.

Positioning and Mounting

Furnace placement and securing procedures.

1. Position furnace in desired orientation (upflow, downflow, horizontal).
2. Level furnace using shims if necessary.
3. Secure furnace to foundation or mounting platform.
4. Install appropriate ductwork connections.
5. Ensure proper clearance around electrical and gas connections.

Tip: Use vibration isolators when mounting on suspended floors.

Venting System

Combustion air intake and flue gas exhaust installation.

1. Install PVC or CPVC vent pipes per local codes.
2. Maintain minimum 1/4" per foot slope toward furnace.
3. Use approved primer and cement for all joints.
4. Keep vent runs as short and straight as possible.
5. Install termination caps with proper clearance from openings.

WARNING! Improper venting can cause carbon monoxide poisoning. Test system for leaks after installation.

Gas Supply Connection

Natural gas line installation and leak testing.

1. Install sediment trap ahead of gas valve.
2. Use approved pipe joint compound or Teflon tape.
3. Pressure test gas line at 14" W.C. for 10 minutes.
4. Check for leaks with soap solution.
5. Verify manifold pressure per rating plate specifications.

CAUTION! Always use leak detection solution; never use matches or open flames to check for gas leaks.

Electrical Wiring

Power supply and control wiring connections.

1. Disconnect power before making electrical connections.
2. Install properly sized disconnect switch within sight of furnace.
3. Connect 115V power supply with proper grounding.
4. Wire thermostat per wiring diagram.
5. Connect humidifier or electronic air cleaner if applicable.

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

Condensate Drain System

Condensate removal and drainage installation.

1. Install condensate trap per manufacturer instructions.
2. Route 3/4" PVC drain line to suitable drain location.
3. Maintain proper slope for drainage.
4. Install neutralizer kit if required by local codes.
5. Test drain system for proper flow.

WARNING! Condensate is acidic and can damage surfaces. Ensure proper drainage away from building foundation.

Startup and Commissioning

Initial startup procedures and system verification.

1. Verify all connections are secure and proper.
2. Restore electrical power and gas supply.
3. Set thermostat to heat mode above room temperature.
4. Observe ignition sequence and flame characteristics.
5. Measure temperature rise and adjust blower speed if necessary.
6. Verify proper vent operation and draft.
7. Check all safety controls and limit switches.

CAUTION! Never bypass safety controls during startup or troubleshooting.

Troubleshooting

Reset: Turn power off for 30 seconds to reset control board.

Service: Contact qualified Lennox dealer for technical support and warranty service.