Clearances - A.O. Smith BTH 120 Service And Parts Manual

Installation: This portion of the handbook will review often overlooked installation considerations, taking note
of necessary instruction requirements for the
BTH 120 - 250 / 966 and 967 Series. The instal-
lation manual covers most of these items in de-
tail. BTH heaters are approved for installation on
combustible flooring. Most can be installed in an
alcove with minimum clearances to combustibles
or non-combustibles of 0 inches from the sides
and rear, 0 inches from vent piping, and 1.5 inches
from the top cover. A 24 inch clearance for all
serviceable parts is recommended. Clearances
may vary between BTH models. See instruction
manual or the label on the heater for clearances
applicable to your specific model.
This illustrates the exterior clearances for these BTH units when installed as direct vent heaters.
Note: 24 inches between inlet and outlet is a minimum. Greater distance is
recommended. In colder climates increasing the 24" minimum to a maximum
practical distance, will reduce the possibility of frost over from side winds blow-
ing exhaust vapors to the air intake of the direct vent.
BTH Model 120
BTH Model 150-199
BTH Model 250
A. O. Smith Water Products Company
©
Irving, Texas 2000
3
Service Handbook
Training Department