Bradford White D75T125 Troubleshooting Manual And Instructions For Service page 9

Commercial 24 volt flue damper series gas water heater
Hide thumbs Also See for D75T125:
Table of Contents

Advertisement

DANGER
120 volt exposure. To avoid personal injury,
use caution while performing this procedure.
Condition:
Pilot lights, no flame signal.
Module continues to spark until
system "Lock Out".
Main burner will not light.
Check for loose or damaged
flame sense lead from pilot to
module. (see illustration 1).
Is flame sense lead okay?
Y
Check for loose or damaged
ground wire(s). Are ground wires
okay?
Y
Check venting conditions or
negative pressure
Is vent system okay?
Y
Is heater condensing causing
pilot interruption?
N
Disconnect white flame sense
lead from ignition module at the
"SENSE" location. Set multi-
meter to the "Micro Amps"
setting ( A) (see note). Check
micro amp reading. Be sure
module is sparking during this
test.
(see illustration 2)
Micro-amp readings
0.000 Micro Amp =
Replace module.
1.0 micro amp or less =
Clean pilot flame rod or replace pilot.
White flame
sense lead from
pilot
N
Repair wire lead
or replace pilot.
Repair ground
N
wire(s) or replace
as needed.
Correct improper
N
venting condition.
Determine cause for
condensing and correct.
Y
Under sized heater or high
demand periods
NOTE:
If multi meter is not capable of
testing micro amps, check
continuity of sense lead. If no
continuity, clean pilot flame rod
or replace pilot.
(see illustration 3)
SERVICE PROCEDURE D24-II
Pilot Operation Testing
CAUTION
Be Careful When Making Voltage
Measurements or Jumping Terminals
Not to Damage or Deform Connectors or
Connector Pins.
Illustration 1
Meter
Probe
Illustration 2
Multi-meter set
to check
continuity.
Meter
Probe
Page 9
Flame rod
Flame rod
Multi-meter set
to micro-amp
setting ( A)
White wire lead
from pilot
Meter
Probe
Meter
Probe
Flame rod
Illustration 3
9

Advertisement

Table of Contents
loading

Table of Contents