SYMPTOM
POSSIBLE CAUSES
CORRECTIVE ACTION
Pilot won’t light,
1. Air in line.
1. Bleed line.
or stay lit
2. Defective thermocouple.
2. Replace thermocouple.
(STANDING PILOT)
3. Pilot flame too low.
3. Adjust pilot flame.
4. Manual reset switch not engaged.
4. Push on button.
Pilot won’t light,
1. Sparker won’t work.
1. Check wire connections.
or stay lit
2. Sparker won’t light pilot.
2.a. Pilot flame too lean.
(I.I.D. PILOT)
2.b. Turn valve to “on” position.
2.c. Check for pilot restriction.
3. Manual reset switch not engaged.
3. Push on button.
THE FOLLOWING IS A LIST OF POSSIBLE CAUSES AND CORRECTIVE ACTIONS
FOR BLOCKED FLUE SWITCH PROBLEMS
POSSIBLE CAUSES
CORRECTIVE ACTION
1. Blockage in vent pipe
1. A) Check vent pipe for blockage, such as bird nest, wasp nest, twigs, leaves, etc.
1. B) Check inside the bottom of the vent pipe to make sure the top of the draft
diverter did not rip the inner liner causing it to block part of the vent opening.
1. C) Check that no insulation from the header plate got caught on top of the draft
diverter when the heater was inserted into the wall.
1. D) Check that the vent cap is properly installed, not shoved too far down on the
vent pipe.
2. Burner is overfiring
2. A) Check the manifold pressure.
2. B) Check the rate, NOTE: This appliance was orificed for elevations up to 2,000
feet. When installed at higher elevations refer to orifice chart in “Controls”
section of instructions for proper orifice size.
3. Improper vent system.
3. Correct vent system.
A) Vent too short
A) The vent should terminate a minimum of 12 feet above the floor. See Figure 1.
Also, the top of the vent must be at least 2 foot above any obstacle within a
10 foot radius, including the roof. See Figure A on Page 4.
B) Restriction in vent
B) All type “B” vents shall extend in a generally vertical direction with offsets not
system caused by
exceeding 45 degrees, except that a vent system having not more than one 60
offsets
degree offset may be allowed.
Any angle greater than 45 degrees from the vertical is considered horizontal.
The total horizontal run of a vent plus the horizontal vent connector shall be
not greater than 75 percent of the vertical height of the vent.
C) Incorrect vent pipe
C) Use listed BW type vent pipe. Do not use transite or any other type of ceramic
pipe for venting. Do not use single wall pipe. When venting into a masonry
chimney the chimney must be properly lined and sized for this gas furnace.
The use of type B or a flexible chimney liner is recommended.
4. Incorrect header plate
4. Consult Figure 6 for correct header plate height.
location.
5. Vent pipe not down on the
5. You must use a base plate (obtained from the vent pipe manufacturer) on top of the
header plate securely
header plate, or wall furnace. This will lock the vent pipe down and prevent the
draft diverter from shoving it up.
6. Loose connections on the
6. Check the connections on both the switch and the gas valve. Tighten if necessary.
vent safety wiring harness
DO NOT BYPASS THE BLOCKED FLUE SWITCH: TO DO
SO COULD EXPOSE THE CONSUMER TO PROPERTY DAMAGE,
PERSONAL INJURY OR POSSIBLE DEATH.
TROUBLE SHOOTING CHART - PILOT AND VALVE - CONTINUED
Page 19
