1. Pressure regulator set too high.
2.
Defective
Regulator.
3. Burner orifi ce too large.
1. Excessive primary air.
2. Burner orifi ce too small.
1. Too much primary air.
2.
Noisy
pilot.
3. Irregular orifi ce causing whistle or
resonance.
4. Excessive gas input.
a. Pressure regulator set too high.
b. Defective regulator.
c. Burner orifi ce too large.
1. Insuffi cient primary air.
2. Clogged main burner ports.
3.
Misaligned
orifi
ces.
4. Clogged fl ue collector.
5. Air shutter linted.
6. Insuffi cient combustion air.
1.
Blocked
venting.
2. Insuffi cient combustion air.
3. Blocked heat exchanger.
4. Air leak into combustion chamber or
fl ue collector.
1. Shut off gas supply immediately!
2. Blocked heat exchanger/venting.
3. Drafts around heater.
4. Negative pressure in building.
5. Blocked fl ue collector.
1. Excessive primary air.
2. Main burner ports clogged near pilot.
3. Pressure regulator set too low.
4. Pilot decreases in size when main
burners come on.
5. Pilot fl ame too small.
6. Drafts around heater.
7.
Improper
venting.
1. Main gas off.
2. Lack of power at unit.
3. Thermostat not calling for heat.
4. Defective limit switch.
5. Improper thermostat or transformer wiring
at gas valve.
6. Defective gas valve.
7.
Defective
thermostat.
8.
Defective
transformer.
20
A. Flame lifting from burner ports.
B. Flame pops back.
C.
Noisy
fl
ame.
D. Yellow tip fl ame (some yellow
tipping on propane gas is
permissible).
E.
Floating
fl
ame.
F.
Gas
Odor.
G. Delayed ignition.
H. Failure to ignite.
1. Reset manifold pressure. Refer to
“Operation”.
2. Replace regulator section of combination
gas valve or complete valve.
3. Check with local gas supplier for proper
orifi ce size and replace. Refer to “Operation”.
1.
Close air shutter. Refer to “Operation”.
2. Check with local gas supplier for proper
orifi ce size and replace. Refer to “Operation”.
1. Close air shutter.
2.
Reduce pilot gas. Refer to “Operation”.
3.
Replace
orifi
ce.
4.
a. Reset manifold pressure.
b. Refer to “Operation”; Replace regulator
section of combination gas valve or
complete valve.
c. Check with local gas supplier for proper
orifi ce size and replace.
Refer
to
“Operation”.
1. Open air shutters. Refer to “Operation”.
2. Clean main burner ports.
3. Replace manifold assembly.
4. Clean fl ue collector.
5. Check for dust or lint at air mixer opening
and around the air shutter.
6. Clean combustion air inlet openings in
bottom panel, see “Installation”.
1. Clean fl ue. Refer to “Installation”.
2. Clean combustion air inlet openings in
bottom panel, see “Installation”.
3. Clean heat exchanger.
4. Determine cause and repair accordingly.
1. Inspect all gas piping and repair.
2. Clean heat exchanger/fl ue.
3. Eliminate drafts. Refer to “Installation”.
4.
See
“Installation”.
5. Clean fl ue collector.
1. Close air shutter. Refer to “Operation".
2. Clean main burner ports.
3. Reset manifold pressure. Refer to
“Operation”.
4. Supply piping is inadequately sized.
Refer to “Installation”.
5. Clean pilot orifi ce. Refer to “Operation”.
6. Eliminate drafts. Refer to “Installation”.
7.
Refer
to
“Installation”.
1. Open all manual gas valves.
2. Replace fuse or turn on power supply.
3. Turn up thermostat.
4. Check limit switch with continuity tester. If
open, replace limit switch.
5. Check wiring per diagrams.
6. Replace gas valve.
7. Check thermostat and replace if defective.
8. Be sure 115 volts is supplied to the trans-
former primary, then check for 24 volts at
secondary terminal before replacing.
SYMPTOMS
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
Table 8 - Power Vented Blowers Troubleshooting Guide
Summary of Contents for IIEB-11
Page 14: ...14 Figure 13 Figure 14...
Page 15: ...15 Figure 15 Figure 16...
Page 30: ...NOTES 30...
Page 31: ...NOTES 31...
Page 32: ...260 NORTH ELM ST WESTFIELD MA 01085 TEL 413 568 9571 FAX 413 562 8437 www mestek com...