Lochinvar 3.5, 2.5 service manual Check inlet gas supply, GAS Piping Size Chart

											Installation & Operation Manual
6 Gas connections (continued)
Table 6B Natural Gas Pipe Size Chart
							TABLE - 6B
						GAS PIPING SIZE CHART
Nominal					Length of Pipe in Straight Feet										Maximum
Iron Pipe															Capacity of Pipe
Size															in Thousands
															of Btu/hr for
Inches	10	20	30	40	50	60	70	80	90	100	125	150	175	200
															gas pressures of
															14 Inches Water
1½	2,150	1,500	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
															Column (0.5
															PSIG) or less and
2	4,100	2,820	2,260	1,950	1,720	1,560	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	a pressure drop
															of 0.5 Inch Water
2½	6,460	4,460	3,610	3,100	2,720	2,460	2,310	2,100	2,000	1,900	1,700	1,540	N/A	N/A	Column (Based
															on NAT GAS,
															1025 Btu/hr per
3	11,200	7,900	6,400	5,400	4,870	4,410	4,000	3,800	3,540	3,300	3,000	2,720	2,500	2,340
															Cubic Foot of
															Gas and 0.60
4	23,500	16,100	13,100	11,100	10,000	9,000	8,300	7,690	7,380	6,870	6,150	5,640	5,130	4,720	Specific Gravity)

Check inlet gas supply

￿WARNING DO NOT adjust or attempt to measure gas valve outlet pressure. Attempting to alter

or measure the gas valve outlet pressure could result in damage to the valve, causing potential severe personal injury, death, or substantial property damage.

The gas piping must be sized for the proper flow and length of pipe, to avoid excessive pressure drop. Both the gas meter and the gas regulator must be properly sized for the total gas load.

If you experience a pressure drop greater than 1 inch w.c. (249 Pa), the meter, regulator, or gas line is undersized or in need of service. Perform the steps below when checking inlet gas supply:

1.Turn the main power switch to the “OFF” position.

2.Shut off gas supply at the manual gas valve in the gas piping to the appliance.

3.Remove the 1/8" pipe plug on the flange to the factory supplied gas shutoff valve and install a suitable 1/8" fitting (field supplied) for the manometer tubing. Place the tubing of the manometer over the tap once the 1/8" fitting is installed as shown in FIG. 6-4.

4.Slowly turn on the gas supply at the factory installed manual gas valve.

5.Turn the power switch to the “ON” position.

6.Adjust the temperature set point on the control panel of the SMART TOUCH control module to call for heat or utilize Service Mode, see page 44 of this manual.

7.Observe the gas supply pressure as the burner fires at 100% of rated input. Percent of burner input will be displayed on the Modulation Screen.

8.Ensure inlet pressure is within specified range. Minimum and maximum gas supply pressures are specified in this section of the manual.

9.If gas supply pressure is within normal range and no adjustments are needed, proceed on to Step 11.

10.If the gas pressure is out of range, contact the gas utility, gas supplier, qualified installer or service agency to determine the necessary steps to provide proper gas pressure to the control.

11.Turn the power switch to the “OFF” position.

12.Shut off the gas supply at the manual gas valve in the gas piping to the appliance.

13.Remove the manometer from the pressure tap on top of the gas valve. Remove the 1/8" (3 mm) field supplied fitting and reinstall the pipe plug removed in Step 3.

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