42
MUA-SVX004B-EN
Troubleshooting
Symptoms
Possible Causes
Corrective Actions
Gas odor
1.
Shut off gas supply
immediately.
2.
Blocked heat exchanger.
3.
Drafts around heater.
4.
Negative pressure in the
building.
5.
Blocked draft hood/flue
connector.
1.
Inspect all gas piping and
repair.
2.
Clean heat exchanger.
3.
Eliminate Drafts. Refer to
installation.
4.
See installation.
5.
Clean draft hood/flue collector.
Delayed Ignition
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 flame too small.
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 orifice. Refer to
operation.
Pilot will not light, or will not stay lit
1.
Main gas off.
2.
Pilot adjustment screw turned
too low on combination main
gas valve.
3.
Air in gas line.
4.
Dirt in pilot orifice.
5.
Extremely high or low gas
pressure.
6.
Pilot valve not opening.
a.
Faulty wiring.
b.
Defective ignition control.
c.
Defective valve.
7.
No spark.
a.
Faulty wiring.
b.
Defective pilot.
c.
Defective ignition control.
d.
Sensor grounded.
1.
Open all manual gas valves.
2.
Increase size of pilot flame.
3.
Purge air from gas supply.
4.
Remove pilot orifice. Clean with
compressed air or solvent.(Do
not ream).
5.
Refer to operation.
6.
a.
Inspect & correct all wiring.
b.
Replace.
7.
Replace.
a.
Inspect & correct all wiring.
b.
Replace
c.
Replace.
d.
Inspect & correct ignition
system.
