HearthStone Sterling-Ht 8532 Owner's Manual & Installation Manual page 29

Symptom
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.
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.
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.
Possible Cause
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
A. Excessive.
B. Burner input underrated.
C. Valve leak if flashback
occurs with burner valve in
off position.
D. Improper gas pipe size.
A. Incorrect air-to-fuel ratio.
A1. Primary air incorrect.
A2. Burner ports plugged.
B. Improper log placement.
Corrective Action
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 for a proper burn.
A. Adjust the air shutter 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.
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.
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