Lochinvar 2072, 502 operation manual Gas connections continued, D, Checking gas supply pressure

3 Gas connections (continued)

Combination gas valve/regulators equipped with integral vent limiters are not required to have vent or relief lines piped to the outdoors. The termination of the vent limited opening on the combination gas valve/regulator complies with the safety code requirements of CSD-1, CF-190(a) as shipped from the appliance manufacturer without the installation of additional vent lines.

Checking gas supply pressure

Use the following procedure to check gas supply pressure.

Installation & Operation Manual

13.Remove the manometer and related fitting from the “inlet” side of the gas valve, replace 1/8" hex plug in gas valve and tighten.

14.Turn on gas supply at the manual valve, turn on L.P. gas at the tank if required.

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

16.Turn the gas valve knob to the “ON” position.

17.Set the electronic temperature control or thermostat to call for heat.

1.	Turn the main power switch to the “OFF” position.
2.	Turn gas valve knobs to the “OFF” position.
3.	Shut off gas supply at the field-installed manual gas cock in
	the gas piping to the unit. If fuel supply is L.P. gas, shut off
	gas supply at the tank.
4.	Remove the 1/8" hex plug, located on the “inlet” side of the
	gas valve. You may also use a tapping on the field-installed

￿WARNING

After completing any testing on the gas system, leak test all gas connections. Apply a soap/water solution to all gas connections while main burners are operating. Bubbles forming indicate a leak. Repair all leaks at once. Do not operate this unit with a leak in the gas train, valves or related piping.

	main manual gas cock or gas piping. Install a fitting in the
	inlet pressure tapping suitable to connect to a manometer
	or magnehelic gauge. Range of scale should be 14" w.c. or
	greater to check inlet pressure.
5.	Turn on gas supply at the manual gas cock, turn on L.P. gas
	at the tank if required.
6.	Turn the power switch to the “ON” position.
7.	Turn the gas valve knobs to the “ON” position. Set the
	electronic temperature control or thermostat to call for
	heat.
8.	Observe the gas supply pressure as all burners are firing.
	Ensure that inlet pressure is within the specified range.
	See Connecting To Gas Supply, page 31 for minimum and
	maximum gas supply pressures.
9.	If gas pressure is out of range, contact gas utility, gas
	supplier, qualified installer or service agency to determine
	necessary steps to provide proper gas pressure to the
	control.
10.	If gas supply pressure is within normal range, turn the
	power switch to the “OFF” position.
11.	Turn gas valve knobs to the “OFF” position.
12.	Shut off gas supply at the manual gas cock in the gas piping
	to the unit. If fuel supply is L.P. gas, shut off gas supply at
	the tank.

Check burner performance by cycling the system while you observe burner response. Burners should ignite promptly. Flame pattern should be stable, see Burner Flames in the Copper-fin2Service Manual. Turn system off and allow burners to cool, then cycle burners again to ensure proper ignition and flame characteristics.

SUPPLYINLET

INLET

PRESSURE

TAP

GASOUTLET

VALVE

CONTROL

KNOB

Figure 3-3_Measuring Gas Supply Pressure at Combination Gas Valve

TABLE - 3D

GAS PIPING SIZE CHART

Nominal					Length of Pipe in Straight Feet										Maximum
Iron Pipe															Capacity of Pipe
Size															in Thousands of
	10	20	30	40	50	60	70	80	90	100	125	150	175	200
Inches															Btu/hr per hour
3/4	369	256	205	174	155	141	128	121	113	106	95	86	79	74	for gas pressures
															of 14 Inches
1	697	477	384	328	292	267	246	256	210	200	179	164	149	138
															Water Column
1 1/4	1,400	974	789	677	595	543	502	472	441	410	369	333	308	287	(0.5 PSIG) or less
															and a pressure
1 1/2	2,150	1,500	1,210	1,020	923	830	769	707	666	636	564	513	472	441
															drop of 0.5 Inch

24,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820 Water Column (Based on NAT

2 1/2	6,460	4,460	3,610	3,100	2,720	2,460	2,310	2,100	2,000	1,900	1,700	1,540	1,400	1,300	GAS, 1025 Btu/hr
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	per Cubic Foot
															of Gas and 0.60

423,500 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)

33