Bosch Appliances 125HX LP specifications GAS Line Sizing, Maximum Inlet GAS Flow Pressure Setting

GAS CONNECTIONS and Gas Regulator GAS LINE SIZING

NOTE: The Aquastar 125 HX is supplied with a gas pressure regulator that must be installed on the heater before attaching the gas supply line. See figure 4. Failure to install the gas regulator as shown in figure 4 will be a violation of CSA certification of the unit. The regulator supplied with the heater is preset for the gas shown on the rating plate to the correct pressure. It is an appliance level regulator designed for (low inlet) pressure (less than 1/2 Psig or 15” W.C.) DO NOT connect to an unregulated or high pressure propane line or to a high pressure commercial natural gas line.

GAS INLET PIPE

PRESSURE TAP

PLASTIC VENT CAP

PRESSURE REGULATOR (with directional arrow on reverse side pointing upward)

Fig. 4 - Installation of Gas Pressure Regulator

The pressure regulator provided with the heater is adjusted to deliver the proper gas pressure (as indicated on the rating plate and in the manual for altitude up to 2000 feet (660 meters) above sea level. On appliances being installed above 2000 ft (660 meters) elevation, the inlet gas pressure should be set at installation to the value shown below.

NOTE: The gas pressures specified below refer to pressures taken at the pressure tap on the gas inlet pipe just above the regulator (See Fig 4). These readings should be taken while the heater is operating at full input — i.e. maximum water flow with the temperature dial selector turned all the way clockwise.

MAXIMUM INLET GAS FLOW PRESSURE SETTING

Altitude	Natural Gas	Liquid Propane
	inches W.C:	inches W.C:
0' - 2.000 ft	5.7"	10.5"
2.000 ft - 4.500 ft	4.6"	8.4"

Above 4.500 ft consult your local gas provider.

-It is strongly recommended that the Natural Gas pipe be Black Iron pipe the entire distance from the outside meter to the inlet of the Aquastar regulator. 1/2” Black Iron pipe up to 10 feet, 3/4” Black Iron pipe up to 40 feet and 1” Black Iron pipe up to 150 feet distances. Flex line tubing is NOT recommended, but if used then oversize it.

-It 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 Aquastar regulator. For semi-rigid copper piping: 5/8” up to 20 feet and 3/4” up to 60 feet distances. For Black Iron piping: 1/2” up to 45 feet and 3/4” up to 160 feet distances. Flex line tubing is NOT recommended, but if used then oversize it.

THESE FIGURES ARE FOR AQUASTAR SUPPLY ONLY, ALL OTHER APPLIANCES IN THE BUILDING WILL NEED TO 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. The drip leg must be accessible and not subject to freezing conditions. Install in accordance with the recommendations of the serving gas supplier.

WARNING: The heater must be disconnected from the gas supply piping system during any pressure testing of that system at test pressures in excess of 0.5 psig.

The water heater must be isolated from the gas supply piping system by closing the manual shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or more than 0.5 psig.

The water heater, including the pressure regulator provided with it, must not be operated at 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 and regulator must be checked for safe operation. Make sure that the regulator vent is protected against blockage.

When your connections are made, check for gas leaks at all joints (not just the ones you made). Apply some soapy water to all gas fittings and gas valve. Soap bubbles are a sign of a leak.

NOTE: Do not apply soap solution to pilot filter screen or pilot orifice area. If you have a leak, shut off the gas. After verifying that required gaskets are in place, 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.

6 720 606 562 (02.03) 7