Ao-smith BTH 120-250(A) User Manual

1A DIVISION OF A.O. SMITH CORPORATIONMc BEE, SOUTH CAROLINAPLACE THESE INSTRUCTIONS ADJACENT TO HEATER ANDNOTIFY OWNER TO KEEP FOR FUTURE REFERENCE.PR

10FIGURE 12INSTALLATION OF VENT SYSTEM WARNINGTHE OPTIONAL INTAKE VENTING ARRANGEMENT AND THE EXHAUSTVENTING ARRANGEMENT MUST BE INSTALLED TO RUN DIRE

11D. Know your own qualifications or those of your contractor. Thesolvent welding technique of joining PVC, PVC cellular core, ABS orCPVC pipe is a sp

12BLOCKED OUTLET PROVER SWITCH(SEE FIGURE 13)The Blocked Outlet Prover Switch is set up to shut the unit off when a build-up of positive pressure in t

13CONNECTION OF GAS PIPE1. When connecting gas pipe to unit, apply wrench to flange only. Note:Do not use wrench on gas valve or gas bracket. See Fig

144. When the system requires water for space heating at temperatureshigher than required for domestic water purposes, a tempering valvemust be instal

15OPERATIONSEQUENCE OF OPERATIONTypical Control/Appliance Operating Sequence1. When the control is initially powered, it enters a test mode and willdi

16NO LOW VOLTAGE (Figure 20)24V AC LED OffNO LOW VOLTAGE, 24V AC LED OffFIGURE 20TEMPERATURE PROBE FAULT (Figure 21)Water Temp LED FlashingTEMPERATURE

17Display Flashes “05” when button is pressed:Display Flashes “15” when button is pressed:Display Flashes “25” when button is pressed:ECO SWITCH OPEN

18ADJUSTMENT PROCEDUREINITIAL START-UPA minimum gas supply pressure of 5.0" (1.25 kPa) W.C. (4.5" or 1.12 kPa)on BTH 150 and 199) for natur

19FOR YOUR SAFETY READ BEFORE OPERATINGWARNING: If you do not follow these instructions exactly, a fire orexplosion may result causing property damag

2These designs comply with the latest version of the American NationalStandard for Gas Water Heaters, Volume III, ANSI Z21.10.3 / CSA 4.3 M 98as an au

20 WARNINGUNDER NO CIRCUMSTANCES SHOULD THE INPUT EXCEED THE RATESHOWN ON THE HEATER RATING PLATE. OVERFIRING COULD RESULTIN DAMAGE OR SOOTING OF THE

21FIGURE 25To dissolve and remove the more stubborn mineral deposits, A.O. SmithUN•LIME® Professional Delimer should be used.A.O. Smith UN•LIME® Profe

22To inspect or replace an anode:The anodes on this heater are easily accessible from the top of theheater making replacement simple and quick.1. Turn

23ONE TEMPERATURE - ONE HEATER HORIZONTAL STORAGE TANKFORCED CIRCULATION WITH OR WITHOUT BUILDING RECIRCULATION DANGERTEMPERATURE SETTING SHOULD NOT E

24*PIPE RELIEF VALVE TO OPEN DRAIN.NOTE: IF TEMPERED WATER ISRECIRCULATED, RETURN LINE SHOULD BECONNECTED AT POINT “A”.INSTALL IN ACCORDANCE WITH LO

25TWO TEMPERATURE - TWO HEATERS HIGH TEMPERATUREWITH OR WITHOUT BUILDING RECIRCULATIONTWO TEMPERATURE - THREE HEATERS (TWO PRE-HEATERS/ONE BOOSTER HEA

26* PIPE RELIEF VALVE TO OPEN DRAIN** 140°F (60°C)TO 150°F (66°C) SHOULD BE MAXIMUM WATERTEMPERATURE MAINTAINED IN THE PRE-HEATERS.120°F (49°C) SHOULD

27NOTE 1: TOGGLE SWITCH CONTROLS 180°F (82°C) WATER CIRCULATION.INSTALL ON OR CLOSE TO DISHWASHER. TOGGLE SWITCH MUST BECLOSED (ON) DURING THE RIN

28MANIFOLD KITSPrecision cut type “L” all copper A.O. Smith manifold kits assure water flow balance of all units. Without this balance, the full water

29CHECKLIST AND SERVICE INFORMATIONIMPORTANTThe installer may be able to observe and correct certain problems whichmight arise when the unit is put in

3 DANGERTHIS WATER HEATER IS EQUIPPED WITH AN ADJUSTABLE THERMOSTATTO CONTROL WATER TEMPERATURE. HOT WATER TEMPERATURESREQUIRED FOR AUTOMATIC DISHWAS

30MOTOR WILL NOT RUN1. Confirm 120V AC to the controller. Also, to verify correct polarity, checkfor 120 V AC between hot supply and ground.If there i

31Model BTH Limited WarrantyA. O. Smith Corporation, the warrantor, extends the following LIMITED WARRANTY to the owner of this water heater.1. THE TA

32A.O. SMITH WATER PRODUCTS COMPANY5621 W. 115TH STREET • ALSIP, ILLINOIS 60803PHONE: 1-800-433-2545 • FAX: 1-800-433-2515 www.hotwater.com • E-MAIL:

4that the water temperature be set for the lowest temperature which satisfiesyour hot water needs. This will also provide the most energy efficientope

5• Do not cover the temperature & pressure relief valve.• Do not cover the instruction manual. Keep it on the side of thewater heater or nearby fo

6less than 100 square inches (645 cm²).If the confined space is within a building of tight construction, air for combustionand ventilation must be obt

7FIGURE 5*NOTE: BTH 250 USES TEE ONAIR INTAKE TERMINALDIRECT VENTHORIZONTAL VENTFIGURE 6DO NOT TERMINATE EXHAUSTOVER PUBLIC AREA WHERECONDENSATE OR

8TRANSMITTED INTO THE LIVING SPACES.IMPORTANTThe vent system must terminate so that proper clearances are maintainedas cited in local codes or the lat

9FIGURE 9IMPORTANTWHEN LOCATING THE TERMINALS ON A SIDEWALL, THE FOLLOWINGSPECIFICATIONS PERTAINING TO TERMINAL LOCATION MUST BEFOLLOWED.1. The intak