Roberts Gorden 300, 200, 350, 400 Gas Valve for Models UHAXS 150, Check Gas Rate, Pressure Switch

SECTION 11: OPERATION AND MAINTENANCE

Figure 14: Gas Valve for Models UHA[X][S] 150 - 400

END VIEW	TOP VIEW
	Regulator
	½PSI
	C
	IN
		ON
Gas Inlet	OFF	Outlet
		Pressure
	Description	Part Number
	Gas Valve 150 - 250 NG	90032505
	Gas Valve 150 - 250 LP	90032506
	Gas Valve 300 - 400 NG	90032520
Inlet Pressure	Gas Valve 300 - 400 LP	90032521

11.2.2Start-Up the Gas Valve (All Gases) 11.2.2.1 Check Burner Gas Pressure

1. Remove the plug in the outlet (burner) pressure test point and connect a pressure tap and a manometer.

2.With the burner firing, measure the pressure on the manometer. To adjust the burner pressure, remove the regulator cover from the valve and turn the regulator adjustment screw to set the required burner pressure as stated in the Technical Data Table for the correct gas and model on Page 49, Section 16.3.

NOTE: If the correct burner pressure cannot be reached, then check the inlet pressure to the valve with the burner firing. See Technical Data Table on Page 49, Section 16.3 for inlet pressure requirement.

Do not continue to adjust the regulator if the pressure is not changing.

If the inlet pressure is too low to allow correct burner pressure setting, then the gas inlet pressure must be corrected before completing the start-up.

Check Gas Rate

1.After burner pressure adjustment, allow the heater to operate for at least 15 minutes and then re-check settings. Adjust pressure setting if necessary.

2.Check gas flow rate at gas meter.

3.Turn off heater and electrical supply.

4.Remove the manometer and refit all covers to the valve and tighten the screw of the outlet pressure tap.

11.2.3 Pressure Switch

The pressure switch is factory pre-set for each model and is not adjustable.

11.2.4 Turning Off the Heater

Set the thermostat to the "OFF" position or lowest setting and the main burner will stop.

The fan will continue to run until it is stopped automatically by the fan thermostat.

Do not use a disconnect switch for control of heater. Disconnect switch will turn off the fan. Heat exchanger could be damaged. Warranty will not cover damage to the heat exchanger if operated improperly. Only use the disconnect switch for turning off heater for service or during off-season.

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