Natco Fire-Coil Volume Water Heaters
Page 25
2.
Touch the other voltmeter lead to the red 24V
terminal on the ignition control.
3.
If the voltmeter reads voltage, the temperature
control and the manual reset hi-limit switch are
not keeping the heater from firing.
4.
Make sure the pilot burner is positioned next to
the main burner (see Figure 37) and there is no
soot or dirt on it.
5.
Make sure the electrode (part of pilot assembly)
is clean, the terminal connection is tight, and the
stainless steel lead is at least 3/8 inch (9.5 mm)
from the heater chassis and other metal parts.
6.
Check for proper spark gap.
5B-9. Testing the Ignition Control
(for standing pilot)
This test will determine if the ignition control is
operating correctly. To test the ignition control for
standing pilot:
1.
Clip one lead from the voltmeter to the yellow
wire terminal on the transformer.
2.
Touch the other voltmeter lead to the terminal on
the gas valve, where the brown wire is attached.
3.
If the voltmeter reads voltage, the temperature
control and the manual reset hi-limit switch are
not keeping the heater from firing.
4.
Make sure the pilot burner is positioned next to
the main burner (see Figure 38) and there is no
soot or dirt on it.
5.
Make sure the electrode (part of pilot assembly)
is clean, the terminal connection is tight, and the
stainless steel lead is at least 3/8 inch (9.5 mm)
from the heater chassis and other metal parts.
6.
Check for proper spark gap.
5B-10. Testing the High Voltage
Ignition Lead
Connections must be tight, and silicone rubber
boots in place. Bare metal parts at the base of the
manifold bracket must be at least 3/8 inch (9.5 mm)
from other metal objects. To test the ignition lead:
1.
Turn the control panel switch to on.
2.
Make sure the temperature control is turned far
enough to call for heat. There will be a loud
clicking noise indicating the pilot electrode is
sparking.
3.
If no sparking is heard, pull the ignition lead
from the ignition control and hold the bare
terminal 1/8 to 3/16 inch (3.2 to 4.8 mm) from
the ignition stud with a pair of insulated pliers
(see Figure 39).
Figure 37. Pilot location (spark ignition).
Figure 38. Pilot location (standing pilot).
Figure 39. High voltage ignition test.
4.
If a spark does not jump the gap, replace the
ignition control.
NOTE: The ignition control cannot be repaired
in the field. If it does not operate properly, replace it.
