Gas Orifice - Bth 300 Thru 500 Models; Orifice Chart - Bth 300 Thru 500 Models - A.O. Smith BTH 120 Service Handbook

GAS ORIFICE - BTH 300 THRU 500 MODELS

Refer to Orifice Chart below for correct gas orifice size. BTH 120 thru 250 Models and all Natural gas
models do not use a gas orifice.
Gas Control Without Orifice Natural Gas

ORIFICE CHART - BTH 300 THRU 500 MODELS

46
Without Orifice
BTH 300 - 500 MODELS
Model/Series
200/201
Natural
Propane (LP) 0.344"
Servicing should only be performed by a Qualified Service Technician
Gas Control With Orifice Propane (LP)
300 400 500
200/201 200/201
N/A N/A N/A
0.344" 0.344"
w/LP Gas Orifice