Hearthstone
Quality
Home
Heating
Products ,
Inc.
ODEL
8521
Sterling
“G”
B-Vent
19
T
ROUBLE
S
HOOTING
Symptom
1. Pilot will not
light.
2. Pilot will not
stay lit after
carefully following
lighting instruction.
3. Pilot burning, no
gas to main burner,
valve knob in the
“ON” position,
on/off/T-stat switch
in
“ON”
position, or
if “
T-stat”
is
selected, T-stat in
“ON”
position.
4. Pilot and burner
come on, but go
out after some
warm-up.
5. Frequent pilot
outage problem.
Possible Cause
A. Insufficient gas pressure,
or air in the pilot line.
B. Pilot orifice plugged.
C. Defective or misaligned
electrode at pilot.
D. Defective ignitor.
A. Low or too high gas
pressure .
B. Defective thermo-couple.
A. If T-stat is selected, or T-
stat or wires defective.
B. Thermopile may not be
generating sufficient voltage.
C. Plugged burner orifice.
A. Inconsistent, or insufficient
flame on Thermopile.
B. Insufficient gas pressure.
A. Pilot may be too low or
blowing, (high), causing the
pilot safety to drop out.
Corrective Action
A. Using the piezosparker, try to light the pilot. If it will not
light, check the inlet gas pressure.
B. Clean or replace pilot orifice.
C. If a match lights the pilot, check the electrode gap and
location. Should be a 3-mm gap in the flame area.
D. Check for a good connection between ignitor and
electrode. Check wire insulation. If properly connected
and no spark, replace ignitor.
A. Check for proper inlet pressure for the gas being used.
B1. Check pilot flame to see that it is impinging on the top
9.5-mm of the thermocouple. Clean and/or adjust pilot for
maximum flame impingement.
B2. Ensure that the thermocouple connection at the gas
valve is tight, and thermocouple is fully inserted into the
pilot bracket and is tight. (Hand tight, plus ¼" turn.).
B3. Check thermocouple output using milli-volt meter.
Insert adapter in between valve and thermocouple. If the
reading is less than 14-mV, replace thermocouple.
A. Check T-stat/wires for proper connections. Place
Jumper wire across terminals at T-stat. If burner comes
on, replace defective wall switch. If OK, place jumper
across T-stat wires at gas valve. If burner comes on,
tighten connections, or replace faulty wires.
B. Check Thermopile output, using a milli-volt meter. Take
the readings across generator terminals of the gas valve.
(TH and TP). Millivolt reading should be greater than 150-
m V. If not, replace Thermopile. If the meter reading is
OK, but the burner does not come on, replace the gas
valve.
C. Remove and check burner orifice, clean or replace.
Note: do not use any metal cleaning device, as this may
damage the orifice.
A. Adjust flame size and assure that the flame is aimed
directly at the Thermopile.
B. Check line pressure to ensure that the correct inlet
pressure is present for the type of gas being used. If
propane pressure is inconsistent, check for water
condensation at the regulator.
A. Clean and/or check the pilot flame for correct
impingement on the thermogenerator and thermocouple.
