R
Ryan PadillaAug 31, 2025
How to ground a Lennox G27M?
- KkfarmerAug 31, 2025
If your Lennox furnace is not working, ensure the unit has a proper ground. Install a main ground to the unit if necessary.
To Next PageTo Next PageHow to ground a Lennox G27M?
If your Lennox furnace is not working, ensure the unit has a proper ground. Install a main ground to the unit if necessary.
How to check if the correct pressure switch is installed on a Lennox G27M?
If your Lennox furnace isn't working, the wrong pressure switch might be installed, or the pressure switch is out of calibration. Check that the proper pressure switch is installed in the unit and replace if necessary.
How to check the 9-pin connector on a Lennox Furnace?
If your Lennox furnace fails to operate, check the 9-pin connector for proper connection to the control board. Also, check the continuity of the multi-plug pin.
How to troubleshoot indoor air blower motor not energizing on a Lennox G27M Furnace?
If the indoor air blower motor in your Lennox furnace does not energize, check for correct wiring and replace any loose connections.
How to check gas pressure at the gas valve on a Lennox Furnace?
If your Lennox furnace isn't working, ensure gas is being supplied to the unit. Check the line pressure at the gas valve, ensuring it doesn't exceed 13” WC for both natural and propane. The line pressure should be a minimum of 4.5” WC for natural gas and 8.0” WC for propane.
How to resolve low pressure differential at the pressure switch on a Lennox furnace?
If your Lennox furnace isn't working, a low-pressure differential at the pressure switch could be the cause. Check for restricted vent inlet or exhaust and remove any blockages. Also, check for proper vent sizing; refer to the installation instructions.
How to check the burner location on a Lennox G27M?
If the burners are not properly located in the burner box of your Lennox furnace, ensure that the burners are firing into the center of the heat exchanger openings. Correct the location of the burners if necessary.
How to check the door interlock switch on a Lennox G27M Furnace?
If your Lennox furnace is not working, check the door interlock switch. Ensure it is activated when the door is closed. Inspect the wire connections to the switch and replace any loose connectors. Check the continuity of the switch in the closed position; replace it if defective.
What to do if my Lennox G27M roll-out switch is open?
If your Lennox furnace isn't operating, check the roll-out switch. First, manually reset it by pushing the top button. Then, check the continuity across the switch; if it's reset but doesn't have continuity, replace it. Also, ensure the wiring connections to the switch are correct. It's important to determine why the roll-out switch was activated before resuming furnace operation.
How to clean the flame sensor on a Lennox Furnace?
If your Lennox furnace is experiencing flame rectification failure, the sense rod might be contaminated. Inspect the sense rod for contamination or any coated surfaces. Clean the sense rod with steel wool or replace the sensor. Avoid using sandpaper, as it can worsen the contamination issue.
General| Model | G27M Series |
|---|---|
| Blower Type | Multi-speed |
| Ignition Type | Hot Surface Ignition |
| Heat Exchanger Material | Aluminized Steel |
| Fuel Type | Natural Gas/Propane |
| Warranty | 5-year parts warranty |
| Stages | Single-stage |
| Blower Motor Type | PSC |
Keep furnace area clear of flammables; ensure unobstructed airflow.
Avoid storing chemicals near unit; do not draw return air from appliance rooms.
Instructions for starting the furnace, noting electronic ignition.
Steps and safety for operating the gas valve.
Procedure for safely turning off the gas supply to the furnace.
