Instruction manual

47
D TROUBLESHOOTING
Troubleshooting Sequence of Operation to Light the Burner
Turn power switch to the ON position
Switch diode should be lit !
No
Yes
Verify the connections to the main electrical supply
and check the fuse on the control board
Turn the heater temperature control
clockwise (should hear a click)
Is the pressure switch at the NC
position ?.
The fan will not start.
- Check if the DL8 diode is lit (transformer lamp control). If it is
not lit, check the transformer.
Turn power on and carefully
check the two terminals, 13 and 14 on the electrical control board
(see fig. 29) for a minimum of 110VAC.
If there is no power, check
power to the heater at the on/off switch on the front panel. Place
the leads of your meter on the outer two terminals of the power
switch with the switch pushed to the ON position. If no power is
present, check the fuse on the electrical control board for
continuity. If there is power at the switch, verify that the high limit
thermostat is working properly by turning the power OFF and
remove one wire from terminal 6 or 7 (110 voltage side) and
check for continuity. If continuity is present, reattach the wire.
- If DL8 is lit, check if DL1 is lit. If DL1 is not lit replace the
heater temperature control. If DL1 is lit, check if DL3 is lit.
If DL3 is not lit replace the pressure switch and/or check the
connections between the pressure switch and the electrical
control board.
No
DL1, DL2, DL3 and DL8 are lit
Yes
The fan will start
- Check for power
between terminals
17 and 18 (see fig.
29) on the control
board. If there is
no power, replace
electrical control
board.
No
The pressure switch
switches from NC
to NO, only if there
is a 0.3 inWC
pressure change.
Yes
The lamp control DL4 diode is not lit.
- Check if the vent air-intake pipes are too long.
- Check if the vent air-intake pipe has an obstruction.
- Check if the two leads inside the fan are dirty or not attached.
- Check if flue condensation is inside the fan (in this case a
condensing trap immediately up to the heater is necessary).
- Check if pressure switch has good connections.
No
DL4 is lit
Yes
Spark starts and
gas valve opens
- Check if DL7 diode is lit.
If not, replace the
electrical control board.
- Check for power
between 25V and 25V
(gnd) on the ignition
module. If voltage is OK,
and the unit doesn't
spark, replace ignition
module. If there isn't
any voltage, replace
control board.
No
DL7 is lit
Yes
The burner lights
After 11 seconds (safety time), spark stops and gas valve closes.
Failure lamp indicator becomes lit (see item 7 Fig. 33 or 34).
- Check if gas switch on front panel is at the ON position.
- Check if gas valve is at the open position. To check the gas valve
for 24VAC, the power must be shut off to reset the cycle. Turn the
power back on and 24VAC should be obtained during that 11
second period.
- Check if the inlet gas pressure is between the maximum and
minimum operating ranges (see TABLE 1). Now check
manifold pressure during the 11 second cycle (see TABLE 1 for
correct manifold pressures).
- Check if the electrodes (flame sensor and ignition) are correctly
positioning on the burner (3-4mm or an 1/8 from the top of the
burner).
- Check if the electrodes are correctly connected to the
ignition module.
No
All diodes are lit except for Dl6.
Spark stops and burner is lit
continuously
Yes
Unit is functioning properly
No
Yes
5J=HJ
The burner stops when heater
reaches the set temperature
If the unit continuosly trips at the safety limit of 210°F (100°C), this
would indicate an excessive amount of air in the heat exchanger
or a faulty heater temperature control. Once the unit trips, the
manual reset button must be pressed by unscrewing the black cap
on the front panel.
A sharp narrow object must be used to completely depress the
button.