SERVICE PROCEDURE D24-II
Pilot Operation Testing
DANGER
120 volt exposure. To avoid personal injury, use caution while performing this procedure.
CAUTION |
Be Careful When Making Voltage |
Measurements or Jumping Terminals |
Not to Damage or Deform Connectors or |
Connector Pins. |
Condition:
Pilot lights, no or low flame signal. Control Display shows “4” or “62” for Error Codes (Service Needed). Control continues to spark until system “Lock Out”.
Main burner will not light.
Check for loose or damaged flame sense
lead from pilot to Control Board. (see
illustration to the right). Is flame sense lead
okay?
Y
Check for loose or damaged ground wire(s) from gas valve to control board. Check continuity of wires with ohmeter. Are ground wires okay?
Y
Check venting conditions or negative
pressure.
Is vent system okay?
Y
Is heater condensing causing pilot
interruption?
N
The microamp output of the pilot may be checked by entering “Service Mode” on the water heater display and pressing “Select” until the flame current is shown. The control must be in the heating mode with the pilot lit to display a reading. See section on accessing service mode on the water heater display.
Micro-amp readings
N
N
N
Y
|
| Meter |
Repair wire lead |
| Probe |
Flame rod | ||
or replace pilot. |
| |
to check |
| |
|
| |
| continuity. |
|
Repair ground |
|
|
wire(s) or replace |
|
|
as needed. |
|
|
| Meter |
|
| Probe |
|
Correct improper |
|
|
venting condition. | Checking pilot flame sensor wire and flame | |
Refer to Installation | rod for continuity. |
|
Instructions |
|
|
Make sure pilot shield is in place |
|
|
and not bent or damaged (refer |
|
|
to section on main burner and |
|
|
pilot assembly) . Determine |
|
|
cause for condensing and |
|
|
correct. |
|
|
(Possible under sized water |
| ȝA |
heater or high demand periods.) | Heating | Flame Current |
| Status Operational | |
NOTE: |
|
|
Check continuity of sense lead | SELECT | SET |
to flame rod. If no continuity, |
|
|
clean pilot flame rod or replace |
|
|
pilot. Check pilot flame |
|
|
appearance - if weak check for |
|
|
clogged pilot orifice, bent pilot |
|
|
tubing, or low inlet gas | Pilot flame sensor microamp output | |
pressure. | shown in display using service mode. | |
(see above illustration) | Pilot must be lit to get reading. | |
0.000 Micro Amp = | Replace control board or pilot if wire is |
| damaged. |
1.0 micro amp or less = | Clean pilot flame rod or replace pilot. |
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