OM-NGB 15
Troubleshooting
Main burner will not light
(spark ignition).
User
a. Is pilot burner lit?
b. Is the boiler filled with water? Is the green light in the start switch
“ON”?
Authorized
Service Rep Only
c. Is the igniter-sensor defective? (X)
d. Is the gas valve defective? (X)
e. Is the spark ignition module defective? (X)
Boiler does not build
pressure with main burner lit.
User
a. Is the steam power take-off valve open or leaking?
b. Is the pressure gauge defective?
Authorized
Service Rep Only
c. Is the air vent leaking steam? (X)
d. Is the solenoid or manual drain valve open or leaking? NOTE:
Excessive make-up water added to the boiler reduces steam
production. (X)
e. Is the burner BTU output low? Check the gas pressure at the
burner. Adjust at the gas valve, if necessary. (X)
Main burner does not shut off
after reaching operating
pressure.
User
a. Is the pressure gauge defective?
b. Is the gas valve defective?
Authorized
Service Rep Only
c. Is the operating pressure switch defective? No adjustment is
allowed. Replace the switch if defective. (X)
Boiler builds pressure but
shuts down. RESET light
comes on.
User
a. Is the water level below the “mid” water level probe? Verify that
the water supply is sufficient to maintain the water level at or
above the “mid” water level probe.
Authorized
Service Rep Only
b. Is the operating pressure switch defective? No adjustment is
allowed. Replace the switch if defective. NOTE: If the high-
limit pressure switch has shut down the unit, it should not be
restarted until the problem which caused the shut-down has
been corrected. (X)
c. Is the “mid” water level probe unable to detect water? Clean the
water level probe and probe well (located in the boiler). (X)
Safety relief valve opens.
Authorized
Service Rep Only
a. Are the operating pressure switch and/or high-limit pressure
switch defective? No adjustment is allowed. Replace defective
switches. (X)
b. Is the safety relief valve defective? Replace with ASME approved
15 PSI valve with “HV” marking. (X)
Boiler blows down
immediately when turned off.
Authorized
Service Rep Only
a. Is the thermostatic switch defective? Check for loose electrical
connections on switch. (X)
Boiler does not drain.
User
a. Is the thermostatic switch defective?
b. Is the solenoid drain valve defective?
c. Are the solenoid drain valve or hoses blocked?
