Hearthstone Quality Home Heating Products, Inc.
Bristol Model 8762
39
Symptom
Possible Cause
Corrective Action
5. Frequent pilot outage
problem in CPI mode.
A. Pilot flame may be too low or
blowing, (high), causing the pilot
safety to drop out.
B. Excessive draft
A. Clean and/or adjust the pilot flame for maximum
impingement on the rectification sensor.
B. Check Restriction settings per this manual.
6. Glass fogs
A. A normal result of gas
combustion in a cold stove.
A1. After the heater has warmed up, the glass should clear.
A2. Leave pilot in CPI mode to keep stove warmer.
7. Blue Flames
A. A normal result during the first
10 to 20 minutes.
A. Flames should begin to turn more yellowish after 20
minutes of burning.
B. If the blue color stays; adjust the air shutter for a proper
burn.
8. Floating flames, lazy ill-
defined, quiet flames,
which roll around,
sometimes completely off
of the port, sometimes
with overly, yellow tips.
Possible sooting. Usually
accompanied by the odor
of aldehydes.
A. Potentially dangerous
incomplete combustion due to
incorrect air to fuel ratio (lack of
combustion air or excessive fuel
delivery I.e. excessive gas
pressure, overrating of appliance).
B. Incorrect air intake/exhaust flow
system. Causes may be:
B1. Blocked burner.
B2. Blocked primary air
B3. Blocked secondary air inlets
C. Incorrect air shutter position.
A. Check the appliance input rate and reduce if necessary.
The air intake/exhaust flow system may be too restrictive or
blocked (the rate at which the exhaust leaves [draft]
determines the rate at which the combustion air is delivered).
Poor draft results in insufficient air delivery or a restricted
exhaust. Correct air intake/exhaust flow system.
B1. Clear ports.
B2. Clear obstructions.
B3. Clear obstructions.
C. If gas pressures are correct and the flames stay the same,
adjust the air shutter(s) for a proper burn.
9. Burner flashback. Air-
gas mixture ignites inside
the burner near the orifice,
usually creating a roaring
noise like a blowtorch. The
problem is an imbalance
of gas flow velocity and
burning speed pattern.
A. Excessive primary air.
B. Burner input underrated.
C. Valve leak if flashback occurs
with burner valve in off position.
D. Improper gas pipe size.
A. Adjust the air shutter(s) for a proper burn.
B. Check input rate. Check input pressure using a
manometer. Confirm correct gas pressure at house meter or
tank (call gas company). Confirm burner orifice size.
C. Replace valve. If above corrections do not eliminate
flashback, replace burner.
D. Correct plumbing.
10. Delayed ignition
(makes a sudden
"whoosh" noise as the
burner lights). This is a
buildup of gas prior to
ignition. This is more
prevalent with propane
(LP) fuel.
A. Incorrect air-to-fuel ratio.
A1. Primary air incorrect.
A2. Burner ports plugged.
B. Improper log placement.
C. Pilot shield not installed
properly.
A1. Adjust the air shutter for a proper burn.
A2. Open ports to allow for proper travel of flames.
B. Reposition logs to eliminate interference with flame travel.
C. Ensure the pilot shield is installed in the proper position (if
present).
11. Surface fissures form
in ceramic burner surface.
A. Normal occurrence during the
first few hours of operation.
A. None. Fissures may form at the first firing
– then remain
stable for the life of the burner.
