Lennox HVAC Unit LGT300H5V

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

Check that sparking stops immediately after flame is sensed

Check with gas company or authorities for local code requirements

Refer to the LGT Installation, Operation and Maintenance instruction

Connect test gauge to the outlet pressure tap on the gas valve

Start the unit and call for second stage heat

Wait five minutes for the unit to reach steady state

Observe the flame stability and color

Compare recorded manifold pressure to values in TABLE 24

Disconnect heating demand after obtaining accurate reading

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

Check with gas company or authorities for local code requirements

Filter Inspection and Maintenance

Access filters through the economizer / filter access door

Check all six 24 X 24 X 2” fiberglass throw-away type filters

Clean or replace filters as necessary

Ensure correct 'AIR FLOW DIRECTION' marking on filter frame when re-installing

Record any issues or observations

Refer to LGT Installation, Operation and Maintenance instruction