A.O. Smith 120 trough 500 Service Handbook page 15

Draft inducers can be used with BTR water heaters to mechanically aid a lazy chimney in
vertical vent applications. They are not designed to allow "through-the-wall" vent
installations. (See Power Venter)
When mechanically venting, the following items are required:
Qty
1 Draft Inducer (up to 300,000Btuh)
1 Draft Inducer (up to 305,000 thru 500,000 Btuh)
1 Draft Prover Switch
1 Relay Switch
A.O. Smith Water Products
Irving, Texas ©2000
BTR TANK TYPE HEATERS
SERVICE HANDBOOK
DRAFT INDUCER
SINGLE UNIT INSTALLATION
Description
14
Part No.
90909
90910
95220
96695
Service Handbook
Training Department