A.O. Smith EQ 280 G Instruction Manual

1TTTTThank Yhank Yhank Yhank Yhank YouououououWARNING: If the information in thismanual is not followed exactly, a fireor explosion may result causing

10Intake/Exhaust Installation Requirements (See figures 6, 7and 14):1. The termination must be a minimum of 12 inches aboveanticipated snow or grade l

11or over areas where condensate could create a nuisance orhazard). This is especially true in colder climates where icebuildup is likely to occur.

12Figure 12 shows the factory standard installation.To change the unit to rear exhaust:1. The vent collar, cover plate and jacket top must be removed.

13GAS CONNECTIONS WARNINGTHIS BOILER IS NOT INTENDED TO OPERATE AT GASSUPPLY PRESSURE OTHER THAN SHOWN ON THE RATINGPLATE. EXPOSURE TO HIGHER GAS S

14TABLE 8. Multiplier TableSpecific SpecificGravity Multiplier Gravity Multiplier0.55 1.04 1.00 0.780.60 (natural) 1.00 1.10 0.740.65 0.96 1.20 0.710

15FIGURE 15. POINT TO POINT WIRING DIAGRAM

16FIGURE 16. SCHEMATIC DIAGRAM

17Lighting Instructions for the G(B/W) 200 through 500 models

18Lighting Instructions for the G(B/W) 650 and 750 models

19Figure 17. WHC 1502 Ignition Control Board.There are five (5) electrical connections that must be made forthe boiler to operate correctly.1. Black

2NEW BOILER LIMITED WARRANTYA. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this hydronic boiler:1. If

209. The combustion blower will run for a 25 second post purgecycle. When the post purge cycle is complete, the blower isde-energized and will coast

21If the ADJUST push-button is held down long enough, the set-point will reach 110°F, the minimum value (or 240°F, the maxi-mum value) and stop. At t

22 DANGERHOT WATER TEMPERATURES REQUIRED FOR AUTOMATICDISHWASHER AND LAUNDRY USE CAN CAUSE SCALDBURNS RESULTING IN SERIOUS PERSONAL INJURY AND/OR DEAT

23ONE GENESIS (MODEL GW) HOT WATER SUPPLY BOILER WITH HORIZONTAL TANKFigure 20. Single boiler with horizontal tank.Figure 21. Tank probe installatio

24ONE GENESIS (MODEL GW) HOT WATER SUPPLY BOILER WITH VERTICAL TANKFigure 22. Single boiler with vertical tank.PRESSURE RELIEF VALVE RATING SHOULD NO

25AUXILIARY EQUIPMENT INSTALLATIONThe following is a brief description of the equipment required forinstallations noted in this manual. All installat

26SPACE HEATING APPLICATIONSControlling of these systems is decided mainly by the type ofbuilding system controlling that is desired. A single boiler

27It is recommended that after installation, the boiler and systemwhen filled should include the proper percentage of cleaningsolution related to appr

28• All wire terminals/connectors are firmly attached to valves,modules, switches, limit controls, etc.• There has been no damage caused by freezing,

29WATER FLOW SWITCHThe Water Flow Switch is installed at the boiler outlet to preventburner operation in the event of inadequate water flow throughthe

3Table 1A: Basic Gas and Electrical ParametersMANIFOLD MANIFOLDMODEL TYPE OF PRESS. PRESS.GB/GW GAS VOLTS/HZ AMPS Inches W.C. kPa200 Natural 120/60 20

305. Restore electrical power and gas supply to boiler.• Check for gas leaks and proper boiler and vent operation.HEAT EXCHANGER PREVENTIVE MAINTENANC

31Start-up InstructionsBefore starting the boiler please review the Boiler's Instruction Manual (AOS Part Number 210889-000)supplied with the boi

32For additional information please refer to the User’s Manual supplied with the boileror contact:A.O. Smith Technical Services at1-800-527-19537 a.m.

4MODELNUMBER "A" "B" "C" "D" "E" "F" "G1" "G2"GBO/GWO-200 3 9 3/4 4

5Table 2: Pump PerformanceTable 3: Recovery CapacitiesTable 4: Heat Exchanger Pressure Drop

6FOREWORD CAUTIONTEXT PRINTED OR OUTLINED IN RED CONTAINS INFOR-MATION RELATIVE TO YOUR SAFETY. PLEASE READCOMPLETELY BEFORE USING APPLIANCE.Detail

7FEATURESIMPORTANTOnly qualified personnel shall perform the initial firing of the heater.At this time the user should not hesitate to ask the start-u

8FOR HOT WATER HEATING SYSTEMS (GB models), the cir-culating pump is NOT provided and must be field-installed.SAFETY FLOW SWITCH (Supplied)The safety

9 WARNINGTHE INSTRUCTIONS IN THIS SECTION ON VENTING THEBOILER MUST BE FOLLOWED TO AVOID CHOKEDCOMBUSTION OR RECIRCULATION OF FLUE GASES. SUCHCONDIT