23
T. Cold air is delivered on start up.
U. Cold air is delivered during heater
operation.
V. Hot surface element not glowing
or NO spark (some models).
W. Ignition source present, but pilot
does not light.
X. Pilot lights — Main valve does not
energize.
Y. Hi-Limit switch tripping.
Z. Noisy power venter.
AA. Power venter will not run.
BB. Power ventor turns on and off
while burners are operating.
1. Be sure fan relay heater terminal 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
ignitor.
3. Set gap to 0.1".
4. Replace pilot assembly.
5. Replace hot surface element.
1. Check all connections - terminal PV feeds
24V to the pilot valve.
2. Check pressure — pressure too high or too
low may cause a problem.
3. Spark should arc from electrode.
4. Check pilot line for kinks. Insure
there are no drafts.
1. Check connections- terminal MV feeds
main valve.
2. Replace pilot assembly.
3. Replace if needed.
4. If present, replace main valve; if not,
replace igniter.
1. Burner orifice may be too large:
verify/replace if required.
2. Increase air flow; check fan size. Check for
proper voltage.
3. Replace.
1. Replace or tighten.
2. Clean power ventor wheel.
3. Realign power ventor wheel.
4. Oil bearings on power ventor motor.
(Refer to label on motor).
1. Check and tighten all wiring connections
per diagrams. See “Electrical Connections”.
2. Replace motor.
3 .Check for 24V across 1 and 3 terminals on
fan relay. If 24V is present, jumper terminals
numbered 2 and 4. If motor runs, the relay
is defective and must be replaced. If 24V is
not present, check wiring per diagrams.
1. Be sure ventor relay terminals are
connected per diagrams.
2. Replace ventor relay.
3. Check motor amps against motor name plate
rating, check voltage, replace power ventor
motor if defective.
4. Refer to label on motor.
SYMPTOMS
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
1. Fan relay heater element improperly
wired.
1. Incorrect manifold pressure or input.
2. Voltage to unit too high.
3. Air throughput 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.
5. Broken hot surface element.
1. Loose ignitor connections .
2. Improper gas pressure.
3. Is ignition source 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 ignitor connections.
2. Cracked or broken sensor ceramic.
3. Check sensor/spark lead for continuity.
4. Measure 24 volts from terminals MV to
terminals MV/PV.
1. Unit is overfiring.
2. Air flow too low
3. Defective switch.
1. Power ventor wheel loose.
2. Power ventor wheel dirty.
3. Power ventor wheel rubbing housing.
4. Bearings are dry.
1. Loose wiring.
2. Defective motor overload protector or
defective motor.
3. Defective power ventor relay.
1. Power ventor relay improperly wired.
2. Defective ventor relay switch.
3. Motor overload protector cycling on and off.
4. Motor not properly oiled.
Table 6 - Tubular Propeller Trouble Shooting Guide
