Sterling QVES - Manual (Page 28)

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1. Thermostat malfunction.
2. Heater runs continuously.
1. Fan relay heater element improperly
wired.
1. Incorrect manifold pressure or input.
2. Voltage to unit too high.
3. Air through put too high.
1. Thermostat not calling for heat.
2. No low voltage.
3. Spark gap closed or too wide.
4. Broken or cracked ceramic on spark
electrode.
1. Loose S8600 connections.
2. Improper gas pressure.
3. Is spark in pilot gas stream?
4. No pilot gas — do not use match to
test - presence of gas is easily
detected by the odor.
1. Loose S8600 connections.
2. Cracked or broken sensor ceramic.
3. Check sensor/spark lead for continuity.
4. Measure 24 volts from terminal MV to
terminal MV/PV.
1. Vertical run of fl ue is too short.
(Standard unit only — as Catagory I )
2. Unit is overfi ring.
3. Air fl ow too low
4. Defective switch.
1. Replace thermostat.
2. Check wiring per diagrams; Check
operation at valve. Look for short
(such as staples piercing thermostat
wiring), and correct; Replace gas
valve; Refer to "Operation".
1. Be sure fan relay heater terminals
are connected per diagrams.
1. Refer to "Operation".
2. Check motor voltage with fan running.
Should be 115 volts AC.
3. Refer to "Operation".
1. Close thermostat contacts.
2. Check for 24V across 24V terminals
of
S8600.
3. Set gap to 0.1".
4. Replace pilot assembly.
1. Check all connections, terminal PV
feeds 24V to pilot valve.
2. Check pressure — pressure that is
either too high or too low may cause
a problem.
3. Spark should arc from electrode.
4. Check pilot line for kinks. Ensure
there are no drafts.
1. Check connections-term. MV feeds
main
valve.
2. Replace pilot assembly.
3. Replace if needed.
4. If present, replace main valve; if not,
replace S8600 Igniter.
1. Lengthen vertical run of fl ue pipe (see
venting).
2. Manifold pressure is too high; adjust.
Burner orifi ces may be too large:
verify/replace if req'd.
3. Increase air fl ow; check fan size.
Check for proper voltage.
4. Replace.
Troubleshooting Guide
SYMPTOMS POSSIBLE CAUSE(S) CORRECTIVE ACTION
T. Too much heat.
U. Cold air is delivered on start
up.
V. Cold air is delivered during
heater
operation.
W. NO Spark
X. Spark present but pilot does
not
light.
Y. Pilot lights — Main valve
does not energize.
Z. Hi-Limit switch tripping.