Mestek IIEB-11, Installation & Parts Manual

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3. Defective fan switch.
4. Lack of power at unit.
1. Fan switch heater element improperly
wired.
2. Defective fan switch.
3. Motor overload protector cycling ON
and OFF.
4. Motor not properly oiled.
1. Improperly wired fan control.
2. Main burners not lighting while
thermostat calls for heat.
3. Defective fan switch.
1. Incorrect gas input.
2.
Heater undersized.
3. Thermostat malfunction.
4. Heater cycling on limit control.
1. Thermostat malfunction.
2. Heater runs continuously.
a. Improper thermostat or transformer
wiring at gas valve.
b. Short circuit.
c. Defective or sticking gas valve.
d. Excessive gas supply pressure.
1. Fan switch 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.
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.
3. Check for 24V across 1 and 3 terminals on fan
time delay switch. If 24V is present, jumper
terminals numbered 2 and 4. If motor runs, the
fan switch is defective and must be replaced. If
24V is not present, check wiring per diagrams.
4. Replace fuse or turn on power.
1. Be sure fan switch heater terminals
are connected per diagrams.
2. Replace fan switch.
3. Check motor amps against motor name
plate rating, check voltage, replace fan
motor if defective.
4. Refer to label on motor.
1. Check all wiring.
2. Refer to H or N symptoms.
3. Replace fan switch.
1. Refer to “Operation”.
2. This is especially true when the heated
space is enlarged. Have the heat loss
calculated and compare to the heater output
(80% of input). Your gas supplier or installer
can furnish this information. If heater is
under sized, add additional heaters.
3. Replace thermostat.
4. Check air movement through heat
exchanger. Check voltage to fan
motor. Clean fan blade and heat
exchanger and oil fan motor.
1. Replace thermostat.
2.
a. Check wiring per diagrams.
b. Check operation at valve. Look for short
(such as staples piercing thermostat
wiring), and correct.
c. Replace gas valve.
d. Refer to “Operation”.
1. Be sure fan switch 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, term. 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.
O. continued
P. Fan motor turns on and off while
burner is operating.
Q. Fan motor will not stop.
R. Not enough heat.
S. Too much heat.
T. Cold air is delivered on start up.
U. Cold air is delivered during heater
operation.
V. No Spark.
W. Spark present but pilot does not
light.
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Power Vented Blowers Troubleshooting Guide
SYMPTOMS
POSSIBLE CAUSE(S) CORRECTIVE ACTION