A.O. Smith BTH 300A, BTH 400A - Manuals

5 The temperature may be adjusted from 80°F/27°C to 180°F/82°C.The thermostat was adjusted to 120°F/49°C before the heater wasshipped from the factory. It is recommended that lower watertemperatures be used to avoid the risk of scalding. It is furtherrecommended, in all cases, that the water tempera...

6 THE HEATER SHALL BE LOCATED OR PROTECTED SO IT ISNOT SUBJECT TO PHYSICAL DAMAGE BY A MOVING VEHICLE. DO NOT LOCATE THE HEATER WHERE NOISE FROM THEE X H A U S T O R I N TA K E W I L L B E O B J E C T I O N A B L E . T H I SI N C L U D E S L O C AT I O N S C L O S E T O O R A C R O S S F R O MWINDOW...

7 CLEARANCES These heaters are approved for installation on combustible flooringin an alcove when the minimum clearances from any combustionconstruction are followed as indicated in Figure 4. In all installations the minimum combustible clearances from anyvent piping shall be 0". Vent piping pas...

10 H e a t e r m u s t b e p r o t e c t e d f r o m f r e e z i n g d o w n d r a fts d u r i n gshutdown periods. WARNING NEVER OPERATE THE HEATER UNLESS IT IS VENTED TOTHE OUTDOORS AND HAS ADEQUATE AIR SUPPLY TO AVOIDRISKS OF IMPROPER OPERATION, FIRE, EXPLOSION ORASPHYXIATION. VENT PIPE TERMINATI...

11 2. The horizontal centerline of the intake vent terminal may not be located lower than the horizontal centerline of the exhaust ventterminal (see Figure 9). FIGURE 9. INSTALLATION SEQUENCE For installations in the City of Los Angeles, California Category IVPVC Pipe such as that manufactured by Br...

12 2. Drill a pilot hole approximately 1/4" (6 mm) outside of the marked circle. This pilot hole is used as a starting point for a saws-all ors a b r e s a w b l a d e . C u t a r o u n d t h e m a r k e d c i r c l e s ta y i n gapproximately one quarter inch outside the line. (This will allowt...

14 HOT SURFACE IGNITER The Hot Surface Igniter is a device that ignites the main burner byhigh temperature (>1800°F or >982°C). When 120VAC is appliedto the igniter, sufficient heat is generated to ignite the main burner.Although improvements have been made to strengthen the igniter,it is frag...

15 LESS, THE APPLIANCE NEED NOT BE DISCONNECTED, BUT MUSTBE ISOLATED FROM THE SUPPLY PRESSURE TEST BY CLOSINGTHE MANUAL GAS SHUTOFF VALVE. BEFORE PLACING THE HEATER IN OPERATION, CHECK FORGAS LEAKAGE. USE SOAP AND WATER SOLUTION OR OTHERMATERIAL ACCEPTABLE FOR THE PURPOSE OF LOCATINGGAS LEAKS. DO NO...

16 4. W h e n t h e s y s t e m r e q u i r e s w a t e r f o r s p a c e h e a t i n g a ttemperatures higher than required for domestic water purposes,a tempering valve must be installed. Please refer to installationdiagrams on pages 23 through 28 in back of manual forsuggested piping arrangements...

18 SELF DIAGNOSTIC CONTROLLER This controller is designed for ignition lockout after three consecutivefailed attempts to light. If lockout occurs, the display lights will matchFigure 17. Along with this, a numeric message will appear in thedisplay. The following list of ERROR CODES illustrates possi...

21 DO NOT USE THIS HEATER IF ANY PART HAS BEEN UNDERWAT E R . I M M E D I AT E LY C A L L A Q U A L I F I E D S E R V I C ETECHNICIAN TO INSPECT THE HEATER AND TO REPLACE ANYPART OF THE CONTROL SYSTEM AND ANY GAS CONTROLWHICH HAS BEEN UNDER WATER. LIGHT THE UNIT IN ACCORDANCE WITH THE OPERATINGINSTR...

22 LIGHTING AND OPERATION INSTRUCTIONS c. Remove the pressure regulator cover screw (Figure 16) and adjust the pressure by turning the adjusting screw with a smallscrewdriver. In this example, with heater running on naturalgas, do not exceed 4.0" (0.996 kPa) Water Column. Clockwise to increase g...

23 WARNING UNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEEDT H E R AT E S H O W N O N T H E H E AT E R R AT I N G P L AT E .OVERFIRING COULD RESULT IN DAMAGE OR SOOTING OF THEHEATER. CATHODIC PROTECTION CAUTION HYDROGEN GAS CAN BE PRODUCED IN A HOT WATER SYSTEMSERVED BY THIS HEATER THAT HAS NOT BEEN U...

26 ONE TEMPERATURE - ONE HEATER HORIZONTAL STORAGE TANK FORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION DANGER TEMPERATURE SETTING SHOULD NOT EXCEEDSAFE TEMPERATURE AT FIXTURES. SEE WATERTEMPERATURE CONTROL WARNING ON PAGE 3.I F H I G H E R P R E H E AT T E M P E R AT U R E S A R ENECESSAR...

27 * PIPE RELIEF VALVE TO OPEN DRAIN. N O T E : I F T E M P E R E D W AT E R I S RECIRCULATED, RETURN LINE SHOULD BECONNECTED AT POINT “A”. INSTALL IN ACCORDANCE WITH LOCALCODES. TWO TEMPERATURE - ONE HEATER HIGH TEMPERATURE WITH OR WITHOUT BUILDING RECIRCULATION DANGER TEMPERATURE SETTING SHOULD NO...

28 TWO TEMPERATURE - TWO HEATERS HIGH TEMPERATURE WITH OR WITHOUT BUILDING RECIRCULATION TWO TEMPERATURE - THREE HEATERS (TWO PRE-HEATERS/ONE BOOSTER HEATER) WITH OR WITHOUT BUILDING RECIRCULATION MUST BE IDENTICAL HEATERS FOR MULTIPLE HEATER INSTALLATION SEE MANIFOLD KITSPECIFICATIONS, PAGE 30. CAU...

31 MANIFOLD KITS Precision cut type “L” all copper A.O. Smith manifold kits assure water flow balance of all units. Without this balance, the full water heatingand storage potential of the system cannot be achieved. Plus, the units with the higher water flow may have a shortened life. Unions shownin...

32 CHECKLIST AND SERVICE INFORMATION IMPORTANT The installer may be able to observe and correct certain problemswhich might arise when the unit is put into operation or when it is re-fired after a prolonged shutdown. HOWEVER, it is recommendedthat only qualified servicemen, using appropriate test eq...

33 Checking these four (4) items first will often result in a timely solutionto the service call. WARNING JUMPING OUT COMPONENTS AND/OR CIRCUITS DURINGTROUBLESHOOTING CAN CAUSE SERIOUS PROBLEMS WITHTHE UNIT’S OPERATING SEQUENCE AND IGNITION SAFETY.IF YOU DO NOT HAVE THE PROPER TEST EQUIPMENT, I.E. A...

34 NOTE: Always turn off and disconnect main supply wiring before servicing the unit. 4. Check connecting wire to the flame sensor. Verify that the flame sensor has not been damaged in any way. 5. Verify that the air supply is adequate. The air inlet screen or blower wheel may be restricted. Also, c...

35 Model BTH Limited Warranty A. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this water heater. 1. THE TANK If the glass-lined tank in this water heater shall prove upon examination by the warrantor to have leaked due to natural corrosion from potable ...