        Wiring Diagram: 10/82
        Model: G12D-110-4
        Serial #: 5883J18901

User's Information Manual at Lennox.com

Local User's Information Manual

Furnace has a Robertshaw 7000 gas valve

The pilot is lit with a match. The pilot is located behind and under the middle of the burners.

18x24x1 or 18x25x1 filter

$31.76 for 2 at Amazon Filtrete MPR 1500 18 x 24 x 1 Healthy Living Ultra Allergen Reduction HVAC Air Filter, 2-Pack

        Sat Oct  6 16:31:52 MDT 2018
        
        Ultra Allergen 1500
        310 microns - 90%
        MERV 12
        pressure drop .15

filtrete.com/3M/ Filtrete ultra allergen Healthy Living Air Filter 1500

        Filtrete 1500 2021DC-9
        18x24x1 	
        2021 	
        2021-6
        MPR 1500
        17 3/4 x 23 3/4 actual dimensions

Nordic pure 12x24x1 MERV 12

        Actual Size of Filter: 17 3/8 x 23 3/8 x ¾

$15.97/1 at lowes Filtrete 1500 MPR Model # 2021DC-9

        Buy 4, Get 15% Off
        4 * 16.97
        price 57.70

Filtrete 1500 MPR Ultra Allergen (Common: 18-in x 24-in x 1-in; Actual: 17.7-in x 23.7-in x 0.7812-in) Electrostatic Pleated Air Filter

Lowes order

        Order #: 340765625
        Purchase Date and Time: 10/18/2017 08:48 AM
        
        Parcel Shipping FREE
        Sales Tax $2.25
        Total $59.95

https://filterbuy.com/merv-mpr-fpr-ratings/

Furnace Fan is shaking

Wed Oct 10 12:09:09 MDT 2018

Replace blower wheel?

        search: Lennox 79a5301
        search: Lennox G12D blower wheel
        search: Lennox Furnace Blower Wheel 21707

repairclinic.com/PartDetail Blower Motor 32868

        Pictures show:
        Century
        MOD ?
        Tipp City, OH
        BLK-HI 6.4A 1/5HP
        
        RepairClinic Item #2345986 | Lennox OEM Part #32868
        
        0.2HP 115Volts 60Hz 6.4 amp 1075 RPM's 3 Speed 
        Open Enclosure Single Phase CCW 2.5" Shaft
        
        Replaces Part Number 77A60
        Replaces Part Number 58709
        Replaces Part Number 32135
        Replaces Part Number P-8-9662
        Replaces Part Number P-8-7504
        Replaces Part Number P-8-7091
        Replaces Part Number P-8-3790
        Replaces Part Number P-8-3530
        Replaces Part Number 77A6001
        Replaces Part Number 32662
        Replaces Part Number 32609
        Replaces Part Number 32484
        
        Elmers Sheet metal motor is possibly Lennox 79a5301
        PUEBLO 719-566-8750

repairclinic.com/PartDetail Lennox Furnace Blower Wheel 21707

        Lennox OEM Part #21707
        This part fits model G12D-110-4
        $82.05
        
        Wed Oct 10 12:33:24 MDT 2018
        Out of Stock.  (Expected Ship Date October 17 - October 19 if ordered today)

cozyparts.com/lennox-parts 21707 BLOWER WHEEL 9-1/2" x 9-1/2", 2170701 - $108.64

RepairClinic.com youtube Noisy Lennox Furnace? Blower Wheel Replacement #16596

4m45s - Center blower wheel and tighten set screw.

This video provides step-by-step instructions for replacing the blower wheel on Lennox furnaces. The most common reason for replacing the blower wheel is when the furnace is loud, and tightening or replacing the set screw on the wheel does not fix the problem.

Repair Log

        power off
        remove upper and lower panel
        discharge motor capacitor
        disconnect motor capacitor wires
        note orientation of thermostat wires
        disconnect thermostat wires
        note orientation of motor wires, then disconnect

hamtramckhardware.com/product_info Lennox 79a5301

        1/5 H.P. 115 Volt P/N 79A5301 Furnace Blower Motor 5KSP29KK 1892
        
        Product# : Special Order
        Manufacturer : Lennox	
        Manufacturer# : 79A5301
        Product status : Used
        SKU# : MOT89C37
        Width(in) : 8
        Height(in) : 8
        Length(in) : 8
        Weight(lb) : 9.0000
        EOQ Quantity :Non Available Now / 10 Sold
        Product model# : 5KSP29KK1892S, 5KSP29KK 1892S
        Views : 11327 views
        Item price : $91.00
        Item Number : 17020

Lennox G12D Furnace