State Industries STC-074 specifications Sequence, Top View

SBN TANK TYPE COMMERCIAL GAS WATER HEATER

SERVICE HANDBOOK

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

Draft Proving (Pressure) Switch Table

		Pressure Setting To
		Close Switch (Inches
SBN Models	Part No.	W.C.)
366	194411-0	(-) 1.60 ± .10"
275	194411-1	(-) 2.00" ± .10"
310	194411-2	(-) 1,75" ± .10"
120, 199, 250,	194411-3	(-) 2.40" ± .10"
400
154, 180, 199	194411-4	(-) 2.60" ± .10"

©2003 18 Technical Training Department

Ashland City, Tennessee