Bosch Appliances 250SX NG, 250SX LP manual Gas line sizing, Measuring gas pressure

Models: 250SX NG 250SX LP

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2.11Gas line sizing

Appliance details

2.11Gas line sizing

BIt is strongly recommended that the Natural Gas pipe be Black Iron pipe the entire distance from the outside meter to the inlet of the gas connection. ¾” Black Iron pipe up to 20 feet (6.1m) and 1” Black Iron pipe up to 70 feet (21.34m) distances. Flex line is NOT recommended, but if used, then oversize the diameter of the flex pipe, keep the length to a minimum and try to keep the flex line as straight as possible.

BIt is strongly recommended that the LP Gas pipe be semi-rigid copper or Black Iron pipe from the outside regulator to the inlet of the gas connection. For semi- rigid copper piping: 5/8” up to 10 feet (3.05m) and ¾” up to 30 feet (9.14m) distances. For Black Iron piping: ½” up to 20 feet (6.1m) and ¾” up to 80 feet (24.38m) distances. Flex line is NOT recommended, but if used, then oversize the diameter of the flex pipe, keep the length to a minimum and try to keep the flex line as straight as possible.

THESE FIGURES ARE FOR 250 SX i SUPPLY ONLY, ALL OTHER APPLIANCES IN THE BUILDING MUST

BE INCLUDED IN THE PIPE SIZING.

National Fuel Gas Code requires that a sediment trap (drip leg) be installed on gas appliances not so equipped. Also, a manual gas shut off valve must be installed on the gas supply line within close proximity of the water heater and be visible from the water heater.

Warning: The heater must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures equal to or more than 0.5 psig.

The water heater must not be piped with gas supply pressures in excess of 0.5 psig. If overpressure has occurred, such as through improper testing of the gas lines or malfunction of the supply system, the gas valve must be checked for safe operation.

When connections are made, check for gas leaks at all joints. Apply some soapy water to all gas fittings. Soap bubbles are a sign of a leak.

Danger: If you have a leak, shut off the gas. Tighten appropriate fittings to stop leak. Turn the gas on and check again with a soapy solution. Never test for gas leaks using a match or flame.

2.12Measuring gas pressure

To measure and verify if adequate gas pressure is being delivered to the water heater, first run a high hot water flow rate and operate other gas equipment on the same

load. Using a manometer, then measure the inlet gas pressure at the inlet gas pressure test port. See Fig. 23. Gas pressures lower than 5" W.C. for Natural Gas or 11" W.C. for LPG will result in insufficient degree rise to the hot water being used. See Gas Connections, chapter 2.10.

Fig. 23 Gas pressure measuring (left tapping)

HIGH ALTITUDE OPERATION

Due to the lower density of air at high altitudes, output must be reduced in installations above 4,000 ft (1,219 m).

Altitude

Natural Gas:

Liquid

 

 

Propane:

 

 

 

0 - 4,000 ft

no

no modification

(0 - 1,219 m)

modification

 

 

 

 

4,000 ft - 8,000 ft

 

 

(1,219 m - 2,438 m)

contact CEC for detailed

 

Above 8,000 ft

instructions

 

 

(above 2,438 m)

 

 

 

 

 

Table 4

Burner output at altitudes greater than 4,000 ft (1,219

m)will be electronically reduced once the control board has been properly adjusted.

6 720 607 057

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Bosch Appliances 250SX NG, 250SX LP manual Gas line sizing, Measuring gas pressure