37
PROBLEM
POSSIBLE CAUSE(S)
CORRECTIVE ACTION
SMOKING AND CARBON
FORMATION
Insuf
fi
cient secondary air
Low gas pressure
Ori
fi
ce too large
Flue clogged
D e f e c t i v e g a s c o n t r o l
(thermostat)
Heater installed in a con
fi
ned
area
1.
2.
3.
4.
5.
6.
Provide ventilation to water heater. Check
fl
ue
way,
fl
ue baf
fl
e and burner
Check with gas utility company
Replace with correct ori
fi
ce
Clean, locate source and correct
Replace gas control (thermostat)
Provide fresh air ventilation
1.
2.
3.
4.
5.
6.
UNABLE TO LIGHT THE
BURNER
Air in gas line
Pressure switch
Blocked exhaust
Wire connection
D e f e c t i v e g a s c o n t r o l
(thermostat)
1.
2.
3.
4.
5.
Purge the air from gas line
Check the pressure switch, make sure the
pressure switch hose is not kinked
Check vent pipe for blockage
Check wire connections
Replace the gas control (thermostat)
1.
2.
3.
4.
5.
SIZZLING, RUMBLING
NOISE
Scale and sediment
Condensation dripping on
burner
1.
2.
Drain/
fl
ush-provide water treatment if needed
See “Strange sounds” section in the Manual
1.
2.
WATER LEAKAGE
Condensation
D r i p p i n g Te m p e r a t u r e &
Pressure Relief Valve
Thermostat does not shut-off
Drain valve dripping/leaking
Tank Leak
1.
2.
3.
4.
5.
See “Condensate” section in the Manual
See “Temperature & Pressure Relief Valve”
section in the Manual
Check the Thermostat
Back
fl
ush to clean out sediment, replace if
necessary.
See “Leakage Checkpoints” section
1.
2.
3.
4.
5.
BLOWER WILL NOT
START
No power to unit
Thermostat set too low
Defective air pressure switch
Defective blower
Disconnected or loose wire
Control locked out
1.
2.
3.
4.
5.
6.
Plug in power cord, check fuses and/or supply
voltage
Turn temperature knob to higher setting
Replace air pressure switch
Replace blower
Repair and reconnect wires
Reset – determine cause of lockout
1.
2.
3.
4.
5.
6.
BLOWER RUNS
CONTINUOUSLY
Air pressure switch not closing
due to insuf
fi
cient draft – check for:
a. Ve n t p i p i n g b l o c k e d
b. Piping length too long
c. Clogged/dirty
blower
Disconnected, torn or blocked
pressure switch hose from
air pressure switch to blower
housing
Defective pressure switch
High limit switch open due to
excessive vent temperature or
defective switch
1.
2.
3.
4.
Determine cause of insuf
fi
cient draft. Check
draft with manometer at pressure switch
(Refer to Table 1 in the Manual for minimum
acceptable draft setting)
a. Remove
blockage
b. Reduce vent length/increase vent size
c. Clean blower wheel
Reconnect or replace pressure switch hose
Replace defective pressure switch
Determine cause of overheating check for:
over
fi
ring, insuf
fi
cient air supply, high ambient
air temperature (once high limit switch activated,
must be replaced)
1.
2.
3.
4.
HOT SURFACE IGNITER
NOT GLOWING
FOLLOWING WARM-UP
PERIOD
Defective hot surface igniter
D e f e c t i v e g a s c o n t r o l
(thermostat)
1.
2.
Replace igniter
Replace gas control (thermostat)
1.
2.
VENT PIPE TOO HOT
(ABOVE 170°F)
Blower does not run when
heater
fi
red
Not enough dilution air to mix
with
fl
ue gases
Air in room too hot for mixing
with
fl
ue gases
Wrong burner ori
fi
ce
1.
2.
3.
4.
Refer to “BLOWER WILL NOT START”
problem
Proper air circulation must be provided for
combustion and dilution of
fl
ue temp
Room air to be used for dilution with combustion
products in
fl
ue should be less than 90°F
Install correct ori
fi
ce
1.
2.
3.
4.