Vanguard Heating VN12A, VN6B Trouble- Shooting, Continued, see Cleaning and, Maintenance, page

TROUBLE- SHOOTING

Continued

OBSERVED	POSSIBLE
PROBLEM	CAUSE		REMEDY
ODS/pilot lights but	1.	Control knob not fully	1.	Press in control knob
flame goes out when		pressed in		fully
control knob is	2.	Control knob not	2.	After ODS/pilot lights,
released		pressed in long enough		keep control knob
				pressed in 10 seconds
	3.	Manual shutoff valve	3.	Fully open manual
		not fully open		shut-off valve
	4.	Thermocouple connec-	4.	Hand tighten until
		tion loose at control		snug, then tighten 1/4
		valve		turn more
	5.	Pilot flame not touch-	5.	A) Contact local
		ing thermocouple,		natural gas company
		which allows thermo-
		couple to cool, causing		B) Clean ODS/pilot
		pilot flame to go out.		(see Cleaning and
		This problem could be		Maintenance, page 20)
		caused by one or both		or replace ODS/pilot
		of the following:		assembly
		A) Low gas pressure
		B) Dirty or partially
		clogged ODS/pilot
	6.	Thermocouple dam-	6.	Replace thermocouple
		aged
	7.	Control valve damaged	7.	Replace control valve

Burner(s) does not	1.	Burner orifice(s) is
light after ODS/pilot		clogged
is lit
	2.	Burner orifice(s)
		diameter is too small
	3.	Inlet gas pressure is
		too low

1.Clean burner orifice(s) (see Cleaning and Maintenance, page 20) or replace burner orifice(s)

2.Replace burner orifice(s)

3.Contact local natural gas company

Delayed ignition of	1.	Manifold pressure is
burner(s)		too low
	2.	Burner orifice(s) is
		clogged

1.Contact local natural gas company

2.Clean burner orifice(s) (see Cleaning and Maintenance, page 20) or replace burner orifice(s)

22

Burner backfiring	1. Burner orifice(s) is
during combustion	clogged or damaged

2. Burner damaged

3. Gas regulator defective

1.Clean burner orifice(s) (see Cleaning and Maintenance, page 20) or replace burner orifice(s)

2.Replace burner

3.Replace gas regulator

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