Gas Line Connection
1.The water heaters covered by this manual are shipped from the factory with 3/4 inch supply gas connections. The supply gas line must not be smaller than 3/4 inch, see Table 5 on page 14. Connect the supply gas line to the water heater's 24 Volt Gas Valve in accordance with all applicable local and national code requirements. Do not use flexible gas piping.
2.Depending on the developed equivalent length and/or the number of appliances connected to a common main, the size of the supply gas line may have to be increased, see Gas Line Sizing on page 39. If the supply gas line must be
Note: Make the transition to the larger supply gas line as close to the supply gas connection as possible.
24 Volt Gas Valve on the water heater from twisting during installation.
6.To prevent damage, care must be taken not to apply too much torque when connecting the supply gas line to the water heater.
7.Install a sediment trap (dirt leg) as shown in Figure 52 on page 39.
8.Install a Main Gas Shutoff valve in the supply gas line as shown in Figure 52 on page 39.
Note: Should overheating occur or the gas supply fail to shut off, turn off the Main Gas Shutoff valve to the water heater.
Gas Line Leak Testing
INSTALL A REDUCER
COUPLING WHEN A
LARGER SUPPLY GAS
LINE IS REQUIRED
FIELD INSTALLED
PIPE NIPPLE
TO MAIN
BURNER
FLOW
24VOLT GAS VALVE
Fire and Explosion Hazard
Use joint compound or Teflon tape compatible with propane gas.
Leak test before placing the
water heater in operation.
Disconnect gas piping and main gas shutoff valve before leak testing.
Install sediment trap in accordance with NFPA 54.
SUPPLY GAS LINE CONNECTION 120,000 & 150,000 Btu/hr MODELS
Figure 53
3.Apply thread sealing compounds (pipe dope/Teflon tape) sparingly and only to the male threads of the pipe joints. Do not apply sealing compound to the first two threads. Use pipe dope or Teflon tape marked as being resistant to the action of liquid petroleum (LP/propane) gases.
SUPPLY GAS CONNECTION |
FACTORY INSTALLED |
TEE FITTING |
LOW GAS PRESSURE |
SWITCH |
COMBUSTION |
BLOWER |
SUPPLY GAS LINE CONNECTION |
199,000 & 250,000 Btu/hr MODELS |
Figure 54
4.Use only a smooth jaw adjustable wrench (such as a monkey wrench) as a back up on the body of the 24 Volt Gas Valve when tightening the first pipe nipple into the body of the valve. Do not use a standard pipe wrench (Stillson wrench) with metal tooth jaws as this may permanently damage the valve.
5.Use a standard pipe wrench (Stillson wrench) as a back up on the first pipe nipple installed above when connecting other fittings and pipe in the supply gas line to prevent the
Any time work is done on the gas supply system perform a leak test to avoid the possibility of fire or explosion.
1.For test pressures exceeding 1/2 psi (3.45 kPa) disconnect the water heater and its Main Gas Shutoff Valve from the gas supply piping system during testing, see Figure 52 on page 39. The gas supply line must be capped when disconnected from the water heater.
2.For test pressures of 1/2 psi (3.45 kpa) or less, the appliance need not be disconnected, but must be isolated from the supply gas line by closing the Main Gas Shutoff Valve during testing.
3.Paint all supply gas line joints and connections upstream of the water heater with a rich soap and water solution to test for leaks. Bubbles indicate a gas leak. Do not use matches, candles, flame or other sources of ignition for this purpose.
4.Repair any leaks before placing the water heater in operation.
Supply Gas Regulator Installation
The water heaters covered in this manual must have a supply gas regulator installed in the supply gas line connected to the water heater. See the Installation Requirements on page 14.
1.A supply gas regulator shall be installed for each water heater on multiple water heater installations.
2.Supply gas regulators must be rated at or above the input Btu/hr rating of the water heater they supply.
3.Supply gas regulators shall have inlet and outlet connections not less than the minimum supply gas line size for the water heater they supply. See Table 5 on page 14.
The Maxitrol
4.Supply gas regulator(s) shall be installed no closer than 3 feet (1 meter) and no farther than 10 feet (3 meters) from the supply gas connection on the water heater.
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