Sequence Of Operation; Top View - State Water Heaters SBN 71-120NE Service Handbook

SBN TANK TYPE COMMERCIAL GAS WATER HEATER
SBN SEQUENCE OF OPERATION
Sequence
1. Thermistors (probes) call for
heat.
2. Inducer fan starts and
provides draft.
3. Hot surface igniter = 20 sec.
warmup.
4. Main gas valve opens 4 sec.
trial for ignition. (Maximum 5
trials.)
5. Main burner ignites and
proves.
6. Thermistors reach the
temperature setting.
7. Main burners "OFF"
- Auto restart after 60 min.
- 20 sec blower "interpurge"
between trials

Top View

©2003
SERVICE HANDBOOK
SBN Models
120, 199, 250,
400
154, 180, 199
18
Draft Proving (Pressure) Switch Table
Close Switch (Inches
Part No.
366 194411-0
275 194411-1
310 194411-2
194411-3
194411-4
Technical Training Department
Ashland City, Tennessee
Pressure Setting To
W.C.)
(-) 1.60 ± .10"
(-) 2.00" ± .10"
(-) 1,75" ± .10"
(-) 2.40" ± .10"
(-) 2.60" ± .10"