Laarsen Associates LG, LD 2D. Combustion and Ventilation Air Supply, 2E. Gas Supply and Piping

Model LG & LD Pool and Spa Heater Page 5

without modification and in accordance with all local, state, provincial and national codes.

Proper ventilation of exhaust and combustion air are essential for the safe operation of the heater.

2D. Combustion and Ventilation Air Supply

All indoor installations must have openings to outside air for combustion, ventilation, and dilution of flue gases from inside the building (see Figure 2 and Table 1). Waterpik Laars does not recommend indoor installations that do not provide combustion air from outside the building.

All outdoor shelter installations (Canada only) must have uninterrupted openings to outside air for combustion and ventilation. The installation must be in accordance with the latest edition of CAN/CGA B149. Waterpik Laars does not recommend outdoor shelter installations that depend on internal air for combustion. Combustion air should be ducted to the heater from outside the structure.

If the heater is installed in a residential garage, or where flammable vapors will be present, the

burners must be 18 inches (457 mm) above the garage floor. Refer to the latest edition of the National Fuel Gas Code for more information. In Canada, refer to the latest edition of the Gas Installation Code, CAN/CGA B149.

2E. Gas Supply and Piping

2E-1. General Instructions

Review the following general instructions before continuing the installation.

WARNING

Do not convert this heater from natural gas to propane gas, or propane to natural. Field conversion could create carbon monoxide gas which can cause property damage, serious injury, or death.

1.Gas piping installation must be in accordance with the latest edition of ANSI Z223.1 and all local codes. In Canada, the installation must be in accordance with CAN- B149.1 or .2 and all local codes that apply.

2.Check the rating plate to make sure the heater is fitted for the type of gas being used. Waterpik Laars heaters, as shipped from the factory, are certified to operate at an altitude of 0 to 3000 feet (0 to 915 m) for natural gas and 0 to 5000 feet (0 to 1525 m) for propane gas in the United States. Or if so ordered, at higher altitudes. For higher altitudes, the heater manifold is marked with a tag or sticker indicating one of the following high altitude operation codes:

Manual Shutoff

Valve

Gas Supply		Union
Inlet
T-Fitting
		To
3" Min.	Nipple	Equipment
		Inlet
(76 mm)
	Cap

Figure 5. The proper design for a sediment trap / drip leg.

a.High altitude (H) - 3,000 to 6,000 feet (915 to 1,830 m) for natural gas and 5000 to 10,000 feet (1525 to 3050 m ) for propane gas.

b.High altitude (J) - 6,000 to 10,000 feet (1830 to 3,050 m)

3.In Canada, the heater rating plate is marked for specific altitude requirements: lo altitude is 0 to 2,000 feet (0 to 610 m) and high altitude (H) is 2,000 to 4,500 feet (610 to 1,370 m) above sea level for natural gas and 0 to 4500 feet (0 to 1370 m) for propane gas.

4.Use the figures in Table 3 to size the gas inlet piping from the gas meter to the heater. Check all local codes for compliance before installing the heater.

Table 3. Natural Gas Pipe Size Requirements

		Distance from Gas Meter
	0-50 feet		50-100 feet		100-200 feet
Heater	(0-15 m)		(15-30 m)		(30-60 m)
Size	in.	(mm)	in.	(mm)	in.	(mm)
125	3/4	(19)	1	(25.4)	1	(25.4)
175	1	(25.4)	1	(25.4)	1-1/4	(31.75)
250	1	(25.4)	1-1/4	(31.75)	1-1/4	(31.75)
325	1-1/4 (31.75)		1-1/4	(31.75)	1-1/2	(38)
400	1-1/4 (31.75)		1-1/2	(38)	1-1/2	(38)
Notes:
1. These numbers are for natural gas (0.65 Sp. Gr.) and are
based on 1/2 inch (13 mm) water column pressure drop.
Check supply pressure with a manometer, and local code
requirements for variations. For liquefied petroleum gas,
reduce pipe diameter one size, but maintain a 3/4 inch
(13 mm) minimum diameter.
2. Check supply pressure and local code requirements
before proceeding with work.
3. Pipe fittings must be considered when determining gas
pipe sizing.