Kit #1 is a single sense electrode (one wire to the electrode, applicable to S/N above 920500001), Kit #2 is a dual sense electrode (two wires to the electrode, applicable to S/N below 920500001).
Tune-Up Kit #1 Contents (links in blue):
Item# 10 Electrode 231933, Single Sense, Above S/N 920500002
Item# 48 Burner Assembly 010701
Item# 21 Limit Switch 231244 (New P# 525020)
Item# 65 Sail Switch 230509 (New P# 525024)
Item#'s 13 & 18 Electrode / Burner Door Gasket Kit 071076 (New P# 525011)
Tune-Up Kit #2 Contents (links in blue):
Item# 10 Electrode 230956, Dual Sense, Below S/N 920500001 (New P# 525019)
Item# 48 Burner Assembly 010701
Item# 21 Limit Switch 231244 (New P# 525020)
Item# 65 Sail Switch 230509 (New P# 525024)
Item#'s 13 & 18 Electrode / Burner Door Gasket Kit 071076 (New P# 525011)
______________________________________________________
Suburban Furnace NT30SP Exploded Parts View Links
Item# 3 Bottom Duct Adapter Gasket
Item# 7 Thermostat, White, 161154
Item# 7 Thermostat, Black, 161210
Item# 10 Electrode 231933, Single Sense, Above S/N 920500001
Item# 10 Electrode 230956, Dual Sense, Below S/N 920500001 (New P# 525019)
Item# 12 Burner Access Door 030764
Item# 13 Electrode / Burner Door Gasket Kit 071076 (New P# 525011)
Item# 18 Electrode / Burner Door Gasket Kit 071076 (New P# 525011)
Item# 21 Limit Switch 231244 (New P# 525020)
Item# 33 On / Off Switch 232351
Item# 35 Ignition Board 521099
Item# 38 Module Board Insulator 070538 (Not used w/ 521099)
Item# 42 Vent Cap & Exhaust Tube Assembly 260573
Item# 43 Intake Tube Assembly 050906
Item# 48 Burner Assembly 010701
Item# 50 Manifold Gasket 070408
Item# 60 Gas Fitting 170374 (New P# 525025)
Item# 61 Room Air Wheel 350113
Item# 65 Sail Switch 230509 (New P# 233356)
Item# 72 Crossover Tube Gasket 070385
Item# 75 OEM Motor, 12VDC, 521137
Item# 75 After-Market Motor, 12VDC, 231207MC (New P# 521137MC)
Item# 77 Combustion Air Housing Assembly 390179BK
Item# 79 Combustion Air Wheel 350110
Item# 81 Combustion Air Housing Gasket 070386
Item# 82 Combustion Air Housing Assembly 390424