28
TROUBLESHOOTING
PROBLEM
POSSIBLE CAUSE
CORRECTIVE ACTION
ODS/pilot lights
but flame goes out
when control knob is
released.
1. Control knob is not fully
pressed in.
2. Control knob is not pressed
in long enough.
3. Equipment shutoff valve is
not fully open.
4. Thermocouple connection is
loose.
5. Thermocouple damaged.
6. Control valve damaged.
1. Press in control knob fully.
2. After ODS/pilot lights, keep control
knob pressed in 30 seconds.
3. Fully open equipment shutoff valve.
4. Hand tighten until snug, and then
tighten ¼ turn more.
5. Replace thermocouple.
6. Contact customer service.
Burner(s) does not
light afterODS/pilot
is lit.
1. Burner orifice is clogged.
2. Burner orifice diameter is
too small.
3. Inlet gas pressure is too low.
1. Clean burner orifice (see Care and
Maintenance, page 25 & 26) or contact
customer service.
2. Contact customer service.
3. Contact your gas supplier.
Delayed ignition of
burner(s).
1. Manifold pressure is too low.
2. Burner orifice is clogged.
1. Contact your gas supplier.
2. Clean burner (see Care and Mainte-
nance, page 25 & 26) or contact cus-
tomer service.
Burner backfiring
during combustion.
1. Burner orifice is clogged or
damaged.
2. Burner is damaged.
3. Gas regulator is damaged.
1. Clean burner orifice (see Care and
Maintenance, page 25 & 26 or contact
customer service.
2. Contact dealer or customer service.
3. Replace gas regulator.
High yellow flame
during burner
combustion
1. Not enough air.
2. Gas regulator is defective.
3. Inlet gas pressure is too low.
1. Check burner for dirt and debris. If found,
clean burner (see Care and Maintenance,
page 25 & 26).
2. Replace gas regulator.
3. Contact your gas supplier.
Gas odor during
combustion.
1. Foreign matter between
control valve and burner.
2. Gas leak. (See Warning
Statement at top of page 27).
1. Take apart gas tubing and remove foreign
matter.
2. Locate and correct all leaks (see “Check-
ing Gas Connections,” page 19).
Heater produces a
clicking/ticking noise
just after burner is lit
or shut off.
1. Metal is expanding while
heating or contracting
while cooling.
1. This is common with most heaters. If
noise is excessive, contact qualified
service technician.
Burner(s) does not
light afterODS/pilot
is lit. (Heater is set
up for NG.)
1. Inlet gas pressure is too
high.
1. Contact your gas supplier.
Summary of Contents for VFL-CO18DT
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