Hydronic Heating Boilers and Domestic Water Heaters
INSTALLATION
Continued
CONNECTING TO GAS SUPPLY
Only supply the gas type specified on the unit's rating plate. This unit is orificed for operation up to 2000 feet altitude. If installing above 2000 feet elevation, consult the appliance manufacturer.
INLET PRESSURE: Measure inlet pressure at the inlet pressure tap located upstream of the combination gas valve(s).
See
TABLE - E
Inlet Pressure
Input | Max. | Min. |
495,000 - 745,000 Btu/hr |
|
|
Nat. Gas | 10.5" w.c. | 4" w.c. |
LP Gas | 13" w.c. | 8" w.c. |
|
| |
985,000 - 2,065,000 Btu/hr |
| |
Nat. Gas | 10.5" w.c. | 4.5" w.c. |
LP Gas | 13" w.c. | 8" w.c. |
|
|
|
MANIFOLD PRESSURE: Measure manifold pressure at the pressure tap on the downstream side of the combination gas valves. The gas regulator on the unit's combination gas valve is adjustable to supply proper manifold pressure for normal operation. See
If you must adjust regulator pressure, follow the instructions under Gas Manifold Pressure Adjustment, page 19. Do not increase regulator pressure beyond the specified pressure setting.
Gas Pressure Test
1.Disconnect the unit from the gas supply piping system during any piping system pressure testing greater than 1/2 PSIG (3.5kPa).
2.Isolate the unit from the gas supply piping system by closing a manual shutoff valve during any piping system pressure testing that is equal to or less than 1/2 PSIG (3.5kPa).
3.Test all gas connections for gas leaks before placing unit in operation.
Gas Piping
To safely operate this unit, you must properly size the gas supply piping. See TABLES- F, G, & H for piping and fitting requirements. Gas pipe size may be larger than heater connection.
The gas connection for models 495,000 to 745,000 Btu/hr is 1 1/4" NPT and on models 985,000 to 2,065,000 Btu/hr the gas connection to these units is 2" NPT.
For ease of service, install a union.
Install a manual main gas shutoff valve, outside of the unit gas connection within six feet of the unit in accordance with the requirements of the National Fuel Gas Code, ANSI Z223.1.
You must provide a sediment trap (drip leg) in the inlet of the gas connection to the unit.
Figure 17 - 495,000 - 745,000 Btu/hr Gas Line Connection Example
Figure 18 - 985,000 - 2,065,000 Btu/hr Gas Line Connection Example
IMPORTANT: Do not block access to the electrical cover plate when installing the sediment trap. The sediment trap must be a minimum of 12 inches from the appliance.
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