Desa GWP20TA, GWP30TA, GWN30TA, GWN20TA Connecting to GAS Supply, Typical Inlet Pipe Diameters

INSTALLATION

Continued

CONNECTING TO GAS SUPPLY

WARNING: This appliance requires a 3/8" NPT (National Pipe Thread) inlet connection to the pressure regulator.

WARNING: A qualified ser- vice person must connect heater to gas supply. Follow all local codes.

WARNING: For natural gas, never connect heater to private (non-utility) gas wells. This gas is commonly known as wellhead gas.

IMPORTANT: For natural gas, check gas line pressure before connecting heater to gas line. Gas line pressure must be no greater than 10.5" of water. If gas line pressure is higher, heater regulator damage could occur.

CAUTION: For propane/LP gas,neverconnectheaterdirectly to the propane/LP supply. This heater requires an external regu- lator (not supplied). Install the external regulator between the heater and propane/LP supply.

For propane/LP gas, the installer must supply an external regulator. The external regulator will reduce incoming gas pressure. You must reduce incoming gas pressure to between 11" and 14" of water. If you do not reduce incom- ing gas pressure, heater regulator damage could occur. Install the external regulator with the vent pointing down as shown in Figure

14.Pointing the vent down protects it from freezing rain or sleet.

CAUTION: Use only new, black iron or steel pipe. Inter- nally-tinned copper tubing may be used in certain areas. Check your local codes. Use pipe of large enough diameter to allow proper gas volume to heater. If pipe is too small, undue loss of volume will occur.

Typical Inlet Pipe Diameters

20,000 Btu/Hr Models - 3/8" or greater

30,000 Btu/Hr Models - 1/2" or greater

Installation must include equipment shutoff valve, union and plugged 1/8" NPT tap. Locate NPT tap within reach for test gauge hook up. NPT tap must be upstream from heater (see Figure 15, page 13).

IMPORTANT: Install an equipment shutoff valve in an accessible location. The equip- ment shutoff valve is for turning on or shutting off the gas to the appliance.

Apply pipe joint sealant lightly to male NPT threads. This will prevent excess sealant from going into pipe. Excess sealant in pipe could result in clogged heater valves.

WARNING: Use pipe joint sealant that is resistant to liquid petroleum (LP) gas.

Install sediment trap in supply line as shown in Figure 15, page 13. Locate sediment trap where it is within reach for cleaning. Locate sediment trap where trapped matter is not likely to freeze. A sediment trap traps mois- ture and contaminants. This keeps them from going into heater controls. If sediment trap is not installed or is installed wrong, heater may not run properly.

Propane/LP

Supply Tank

External

Regulator

Vent

Pointing

Down

Figure 14 - External Regulator With Vent

Pointing Down

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