Lennox HVAC Unit LGT240H5V

Check local code requirements with gas company or authorities

Refer to the LGT Installation, Operation and Maintenance instruction

Remove lead from sensing electrode and install a 0-50DC microamp meter in series

Reconnect power and adjust thermostat for heating demand

Compare flame current reading to TABLE 25 when flame is established

Disconnect power to unit before disconnecting meter

Ensure sensor wire is securely reconnected before reconnecting power to unit

If meter scale reads 0, disconnect power and reconnect leads for proper polarity

Preliminary and Seasonal Checks

Ensure the unit is installed according to installation instructions and applicable codes.

Inspect all electrical wiring for loose connections and tighten as required.

Check refrigerant lines for good condition and ensure they do not rub against the cabinet or other lines.

Check voltage to ensure it is within the range listed on the nameplate.

Is the voltage within the range listed on the nameplate?

Recheck voltage and amp draw with unit running.

Is the voltage within range while the unit is running?

Inspect and adjust blower belt.

Check with gas company or authorities for local code requirements

Refer to the LGT Installation, Operation and Maintenance instruction

Ensure main manual shut-off valve is labeled

Ensure main power disconnect is labeled

Disconnect and isolate the gas valve

Ensure pressure does not exceed 0.5 psig

Check with gas company or authorities for local code requirements

Refer to the LGT Installation, Operation and Maintenance instruction

Move test gauge to the outlet pressure tap on unit gas valve GV1 and/or GV3

Verify manifold pressure is factory set

If manifold pressure is incorrect, replace the valve

Ensure gas valve cycles off completely and immediately in the event of gas or power failure

Use manual shut-off knob to immediately shut off gas supply if necessary

Connect a shut-off valve between the manometer and the gas tap for safety

Verify local code requirements with gas company or authorities

Monitor combustion air inducer operation

Check that combustion air inducer is drawing fresh air and expelling exhaust gases

Ensure combustion air prove switch closes during inducer operation

Confirm ignition control activates first stage operator of gas valve

Verify sparking stops immediately after flame is sensed