A.O. Smith BTH 300A, BTH 400A warranty HOT Surface Igniter, GAS Piping, Connection of GAS Pipe

HOT SURFACE IGNITER

The Hot Surface Igniter is a device that ignites the main burner by high temperature (>1800°F or >982°C). When 120VAC is applied to the igniter, sufficient heat is generated to ignite the main burner. Although improvements have been made to strengthen the igniter, it is fragile and care must be taken when handling the igniter to prevent breakage.

GAS PIPING

Contact your local gas service company to ensure that adequate gas service is available and to review applicable installation codes for your area.

Size the main gas line in accordance with Table 3. The figures shown are for straight lengths of pipe at 0.5 in. W.C. (125Pa) pressure drop, which is considered normal for low pressure systems Note that fittings such as elbows and tees will add to the pipe pressure drop.

CAUTION

DO NOT USE FLEXIBLE GAS PIPING.

TABLE 3. MAXIMUM CAPACITY OF PIPE IN CUBIC FEET OF GAS PER HOUR (Based upon a Pressure Drop of 0.5 inch Water Column and 0.6 Specific Gravity Gas and max. gas pressure of 0.5 psig).

	LENGTH		NORMAL IRON PIPE SIZES (INCHES)
	IN		INPUT IN THOUSANDS BTU/HR
	FEET	1 1/4"	1 1/2"	2"	2 1/2"	3"	4"
10		1400	2100	3960	6300	11000	23000
20		950	1460	2750	4360	7700	15800
	30	770	1180	2200	3520	6250	12800
40		660	990	1900	3000	5300	10900
	50	580	900	1680	2650	4750	9700
60		530	810	1520	2400	4300	8800
	70	490	750	1400	2250	3900	8100
	80	460	690	1300	2050	3700	7500
90		430	650	1220	1950	3450	7200
100		400	620	1150	1850	3250	6700
125		360	550	1020	1650	2950	6000
150		325	500	950	1500	2650	5500
	175	300	460	850	1370	2450	5000
200			430	800	1280	2280	4600

	LENGTH		NORMAL IRON PIPE SIZES (INCHES)
	IN			INPUT IN KW
	METERS	1 1/4"	1 1/2"	2"	2 1/2"	3"	4"
3.0		410	615	1160	1845	3221	6735
6.1		278	428	805	1277	2255	4626
9.1		225	346	644	1031	1830	3748
12.2		193	290	556	878	1552	3192
	15.2	170	264	492	776	1391	2840
18.3		155	237	445	703	1259	2577
21.3		143	220	410	659	1142	2372
	24.4	135	202	381	600	1083	2196
27.4		126	190	357	571	1010	2108
	30.5	117	182	337	542	952	1962
	38.1	105	161	299	483	864	1757
45.7		95	146	278	439	776	1610
53.3		88	135	249	401	717	1464
61.0			126	234	375	688	1347

WARNING

THE HEATER IS NOT INTENDED FOR OPERATION AT HIGHER THAN 11.0" WATER COLUMN (2.74 Kpa) FOR NATURAL GAS AND 14.0" W.C. (3.49kPa) FOR PROPANE GAS SUPPLY PRESSURE. HIGHER GAS SUPPLY PRESSURES REQUIRE SUPPLEMENTAL REDUCING SERVICE REGULATION. EXPOSURE TO HIGHER GAS SUPPLY PRESSURE MAY CAUSE DAMAGE TO THE GAS CONTROLS WHICH COULD RESULT IN

FIRE OR EXPLOSION. IF OVERPRESSURE HAS OCCURRED SUCH AS THROUGH IMPROPER TESTING OF GAS LINES OR EMERGENCY MALFUNCTION OF THE SUPPLY SYSTEM THE GAS VALVE MUST BE CHECKED FOR SAFE OPERATION. MAKE SURE THAT THE OUTSIDE VENTS ON THE SUPPLY REGULATORS AND THE SAFETY VENT VALVES ARE PROTECTED AGAINST BLOCKAGE. THESE ARE PARTS OF THE GAS SUPPLY SYSTEM, NOT THE HEATER. VENT BLOCKAGE MAY OCCUR DURING ICE STORMS. IT IS IMPORTANT TO GUARD AGAINST GAS VALVE FOULING FROM CONTAMINANTS IN THE GAS WAYS. SUCH FOULING MAY CAUSE IMPROPER OPERATION, FIRE OR EXPLOSION.

IF COPPER SUPPLY LINES ARE USED THEY MUST BE INTERNALLY TINNED AND CERTIFIED FOR GAS SERVICE.

BEFORE ATTACHING THE GAS LINE BE SURE THAT ALL GAS PIPE IS CLEAN ON THE INSIDE.

TO TRAP ANY DIRT OR FOREIGN MATERIAL IN THE GAS SUPPLY LINE, A DIRT LEG (SOMETIMES CALLED A SEDIMENT TRAP OR DRIP LEG) MUST BE INCORPORATED IN THE PIPING (SEE FIG. 14). THE DIRT LEG MUST BE READILY ACCESSIBLE AND NOT SUBJECT TO FREEZING CONDITIONS. INSTALLINACCORDANCE WITH RECOMMENDATIONS OF SERVING GAS SUPPLIERS. REFER TO THE NATIONAL FUEL GAS CODE OR THE NATURAL GAS AND PROPANE INSTALLATION CODE CSA B149.1.

FIGURE 14.

CONNECTION OF GAS PIPE

1.When connecting gas pipe to unit, apply wrench to flange only. Note: Do not use wrench on gas valve or gas bracket.

2.PERFORM THE GAS LEAK TEST ANY TIME WORK IS DONE ON A GAS SYSTEM TO AVOID THE POSSIBILITY OF FIRE OR EXPLOSION WITH PROPERTY DAMAGE, PERSONAL INJURY OR LOSS OF LIFE.

The Gas Leak Test is performed as follows: Paint pipe connections upstream of gas control with a rich soap and water solution to test for leaks before operating main burner. Bubbles indicate gas leak. To stop leak, tighten pipe connections. After piping connections are checked, turn on main burner. With main burner in operation, paint pipe joints (including flanges), pilot gas tubing connections and control inlet and outlet with rich soap and water solution. Bubbles indicate gas leak. To stop leak, tighten flange screws, joints and pipe connections. Replace part if leak can’t be stopped.

To prevent damage, care must be taken not to apply too much torque when attaching gas supply pipe to gas valve inlet.

Apply joint compounds (pipe dope) sparingly and only to the male threads of pipe joints. Do not apply compound to the first two threads. Use compounds resistant to the action of liquefied petroleum gases.

DISCONNECT THE APPLIANCE AND ITS MANUAL GAS SHUTOFF VALVE FROM THE GAS SUPPLY PIPING SYSTEM DURING ANY SUPPLY PRESSURE TESTING EXCEEDING 1/2 PSIG (3.45Kpa). GAS SUPPLY LINE MUST BE CAPPED WHEN DISCONNECTED FROM THE HEATER. FOR TEST PRESSURES OF 1/2 PSIG (3.45Kpa) OR

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