1.Turn the main power switch to “OFF” position.
2.Shut off gas supply at the manual gas cock in the as piping to the appliance. If fuel supply is LP gas, shut off gas supply at the tank.
3.Remove the 1/8" hex plug from the gas pressure test port located on the inlet gas supply connection at the rear of the appliance. Install a fitting in the inlet pressure tapping suitable to connect to a manometer or magnahelic gauge. Range of scale should be 14 inch w.c. or greater to check inlet pressure.
4.Turn on gas supply at the field installed manual gas cock, turn on LP gas at tank if required.
5.Turn the power switch to “ON” position and ensure that the Run/Stop switch is in the “Run” position.
6.Adjust the temperature setpoint on the Command Display to call for heat.
7.Observe the gas supply pressure as the burner fires at 100% of rated input. Percent of burner input will be displayed on the Command Display.
8.Ensure inlet pressure is within specified range. Minimum and Maximum gas supply pressures are specified in Gas Supply section of this manual.
9.If gas pressure is out of range, contact the gas utility, gas supplier, qualified installer or service agency to determine necessary steps to provide proper gas pressure to the control.
10.If gas supply pressure is within normal range, proceed to remove gas manometer and replace pressure tap fittings in the gas piping to the appliance.
11.Turn the power switch to “OFF” position.
12.Shut off gas supply at the manual gas cock in the gas piping to the appliance. If fuel supply is LP gas, shut off gas supply at the tank.
13.Remove the manometer and related fittings from gas pressure test port at the inlet gas supply connection to the appliance. Replace 1/8" hex plug in gas pressure test port and tighten.
14.Turn on gas supply at the manual valve, turn on LP gas at tank if required.
15.Turn the power switch to “ON” position.
16.Adjust the temperature setpoint on the Command Display to the desired water temperature so the appliance will call for heat.
17.Check burner performance by cycling the system while you observe burner response. The burner should ignite promptly. Flame pattern should be stable, see
IMPORTANT
Upon completion of any testing on the gas system, leak test all gas connections with a soap solution while the main burner is firing. Immediately repair any leak found in the gas train or related components. DO NOT operate an appliance with a leak in the gas train, valves or related gas piping.
CHECKING MANIFOLD
GAS PRESSURE
There is a pressure test tree located in the top chamber of the appliance. This pressure test point can be accessed by swinging out the front control panel. The pressure test tree is mounted on the front edge of the combustion air blower. It consists of an angle support and four test cocks. There is one cock for positive air and one for negative air, one cock for positive gas and one for negative gas. Manifold pressure measurement will utilize both the positive and negative test points for gas.
1.Open the front controls panel and swing the controls out. Locate the pressure test tree on the front edge of the combustion air blower. The positive and negative gas pressure terminals will be used to check differential gas pressure from the gas manifold and the air box. Each gas pressure connection point will have a small manual cock to attach a hose.
2.Connect a hose from the positive gas and the negative gas to each of the two sides of a manometer. This will allow the two pressure points to be measured at the same time. Open the two gas pressure test point cocks.
3.Set the Command Display to a set point which will fire the burner at 100% of rated input.
4.As the appliance comes on and fires, record the inches of water column of displacement on both sides of the manometer. The sum of these two readings as they are effected by the two gas pressures is the differential manifold pressure.
5.The differential manifold gas pressure should be 3.5 inches of water column (+ 0.1" w.c.) when the burner is firing at 100% of rated input.
6.If the differential manifold pressure is not 3.5 inches water column (+ 0.1" w.c.), recheck the gas
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