Hydronic Heating Boilers and Domestic Water Heaters
INSTALLATION
Continued
Figure 21 - Measuring Manifold Gas Pressure
2.Turn the power switch located in the lower left corner behind the control panel access door to the “O” or “OFF” position.
3.Remove the top front jacket access panels to access the gas valve(s).
4.Locate the reference hose on the first gas valve which goes from the vent fitting on the gas valve to the barbed fitting on the deck of the unit (see Figure 21).
5.Remove the flexible cap from the barbed fitting on the "tee" located in this line and hook one side of the manometer, or
6.Remove the 1/8" hex plug from the manifold pressure tap on the gas valve (see Figure 21). Retain plug for future use.
7.Install a fitting in this tap that is suitable for connection of a hose to a manometer, or (+) side of a magnahelic gauge (see Figure 21).
8.Turn the power switch to the “I” or “ON” position.
9.Push the reset button(s) for the ignition control(s), if necessary.
10.Set the temperature control to call for heat (see Setting Temperature Control, page 29).
11.Once the unit is firing, the manometer/magnahelic will reflect the net manifold gas pressure. Compare this reading to the respective value in
12.If adjustment is necessary, remove the regulator cover screw on the gas valve. Note: If the gas valve under adjustment is located on a manifold assembly monitored by an igniter, the unit may shut down and recycle when the regulator cover screw is removed. This is normal.
13.Turn the regulator adjustment screw “clockwise” to raise the regulator gas pressure. Turn the regulator adjustment screw “counterclockwise” to lower the regulator gas pressure.
14.Replace the regulator cover screw and make sure it is tight for proper operation.
15.Read the value on the manometer/magnahelic and compare it to the values in
16.Repeat this adjustment procedure for each gas valve as necessary to adjust to the proper manifold gas pressure.
17.Remove hoses, replace and tighten plugs and caps when complete.
18.Replace top front upper jacket access panels and control panel door in reverse order.
19.If proper ignition and burner operation is not achieved after checking gas supply pressure, see Cleaning and Maintenance, page 41 for Combustion Air Fan Adjustment. Follow the procedure to adjust the combustion air fans as necessary.
TABLE - I
NET MANIFOLD PRESSURE
Regulator Pressure Less
Front Chamber Pressure
Nat. Gas (495,000 | - 745,000 Btu/hr) | 1.8" w.c. |
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Nat. Gas (985,000 | - 2,065,000 Btu/hr) | 1.2" w.c. |
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LP Gas (495,000 - 2,065,000 Btu/hr) | 4.6" w.c. | |
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TABLE-H
CONNECTING TO WATER SUPPLY
Inlet and Outlet Connections
For ease of service, install unions on the water inlet and water outlet of the unit. The connection to the unit marked “Inlet” on the header should be used for return from the system. The connection on the header marked “Outlet” is to be connected to the supply side of the system.
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