Vermont Casting 3032, 3033 Vermont Castings UVS27 Vent-FreeGas Heater, Condition, Possible Cause

Vermont Castings UVS27 Vent-Free Gas Heater

Troubleshooting cont’d.
CONDITION	POSSIBLE CAUSE	SOLUTION

Pilot lights but flame goes out when Control Knob is released.

Pilot flame is lifting.

Thermopile

Thermo- couple

ST121a

Pilot flame is weak - does not touch Thermocouple.

1.Control Knob not fully depressed or held in long enough.

2.Gas supply line shut-off valve is not fully open.

3.Thermocouple connection is loose at the Control Valve.

4.Pilot flame does not touch the Thermocouple. (Figs. 29, 30) This can be caused by:

A)Incorrect gas pressure, and/or

B)other conditions that should be identified only by a qualified service technician.

5.Thermocouple is damaged.

6.Control Valve is damaged.

1.Depress Control Knob fully and hold in for a full 30 seconds.

2.Fully open gas supply line shut- off valve.

3.Inspect and tighten securely.

4.A) Call local gas supplier. Adjust inlet supply pressure to specifica- tion: NG; 5.5” w.c.-14.0”w.c. LP; 11.0” w.c.-14.0”w.c.

B)Call local gas service techni- cian.

5.Call local gas service technician.

6.Call local gas service technician.

Correct LP Pilot Flame. Correct NG Pilot Flame.

Pilot lights but Main Burner does not.

1.Gas supply line shut-off valve is not fully open.

2.Foreign material is blocking Burner ports.

3.Main Burner orifice is clogged.

4.Thermostat or remote switch not activated on JUVS.

5.Bad Thermopile.

1.Fully open gas supply line shut- off valve.

2.Insptect and clear debris away from Burner ports.

3.Call local gas service technician.

4.Set thermostat to higher tem- perature or check remote switch.

5.Call local gas service technician.

Main Burner shuts off and Pilot	1. Insufficient fresh air.	1. Determine that adequate ventila-
flame goes out while in operation.		tion exists to provide sufficient
		fresh air. Open a window or
		provide additional ventilation.
		(See Fresh Air Requirements,
		Pages 6-7)
	2. Incorrect inlet supply pressure.	2. Call local gas supplier. Adjust
		inlet supply pressure to specifica-
		tion: NG; 5.5” w.c.-14.0”w.c. LP;
		11.0” w.c.-14.0”w.c.

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