Gas Supply And Gas Pipe Sizing; General; Gas Connections - Lochinvar 540H Installation Manual And Owner's Manual

On-demand water heater

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Table of Contents

• Do not use this water heater with any gas other than the one listed on the rating plate.

• Ensure that any and all gas regulators used are operating properly and providing gas

pressures within the specified range shown below. Excess gas inlet pressure may cause

serious accidents.

WARNING

• Conversion of this unit from natural gas to propane or vice versa will void all warranty.

Contact your local distributor to get the correct unit for your gas type. The manufacturer

is not liable for any property and/or personal damage resulting from gas conversions. In

Canada, contact tech support at 888.479.8324 for options.

• Failure to observe these warnings could result in severe personal injury, carbon monoxide

poisoning, or death.

• The minimum and maximum inlet gas pressures are:

Gas type

Natural Gas

Propane

• Inlet gas pressures that fall outside the range of values listed above may adversely affect the performance of

the water heater. These pressures are measured when the water heater is in full operation and in standby.

• Inlet gas pressure must not exceed the above maximum values; gas pressure above the specified range will

cause dangerous operating conditions and damage to the unit.

• Until testing of the main gas line supply pressure is completed, ensure the gas line to the water heater is

disconnected to avoid any damage to the water heater.

• If the gas supply pressure to the heater is greater than the specified maximum, a field-supplied regulator is

required. The regulator must lower the gas pressure within the approved range.

- Install the gas regulator according to the manufacturer's instructions.

- The regulator must be sized for the water heater input and provide the specified pressures that are listed

on the rating plate.

- In the absence of minimum install distance stated by the regulator manufacturer, it is recommended

that there is at least 3 ft (1 m) of piping between the regulator outlet and the water heater's inlet gas

connection.

1. Install a manual gas shutoff valve between the water heater and the gas supply line.

2. When the gas connections are completed, it is necessary to perform a gas leak test either by applying soapy

water to all gas fittings and observing for bubbles or by using a gas leak detection device.

• The water heater and its individual shutoff valve must be disconnected from the gas supply piping

system during any pressure testing of that system at test pressures in excess of 1/2 psi (3.5 kPa).

• The water heater must be isolated from the gas supply piping system by closing its individual manual

shutoff valve during any pressure testing of the gas supply piping system at test pressures equal to or

less than 1/2 psi (3.5 kPa).

3. Always purge the gas line of any debris and/or water before connecting to the gas inlet.

Size the gas pipe appropriately to supply the necessary volume of gas required for

NOTICE

the water heater using ANSI Z223.1/NFPA 54 in the USA or B149.1 in Canada or

local codes. Otherwise, flow capabilities and output temperatures will be limited.