Roberts Gorden 250, 200, 350, 150 Begin Start-Up, Before Operating the Heater, on Page 28, Figure

UHA STANDARD UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL

11.2 Begin Start-Up

11.2.1 Before Operating the Heater

To ensure that all the controls are in safe working order, operate the heater for the first time with the isolating gas valve turned off and power supply turned on.

1.Turn off the isolating gas valve.

2.Turn up the thermostat above room temperature. The automatic ignition sequence will now begin as described

on Page 28, Figure 13.

There will be no ignition of the burner and lockout will occur, which proves the controls are operating correctly.

Figure 13: Automatic Burner Control Sequence

Thermostat 24 V

Flue Blower

Pressure P

Switch C

Ignition Spark Start Gas Valve

Flame Signal

Axial Fan

Burner Sequence for Ignition Control
START	RUN	SHUT DOWN
30 Seconds Purge*		30 Seconds Post Purge
NO
NC
ts = 10 Seconds
30 Seconds Delay		90 Seconds Delay

*Purge time begins at pressure switch change over.

Required Incoming Signals		If at any stage the flame fails, the control will retry
	Signals Output By Control	for ignition. The control has four trials for ignition
		before a one hour lockout.

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