Bradford White HE-4-50S6FSX - Manual (Page 28)

Page 28
Flammable Vapor Sensor Testing (cont’d)
Step 3. Using a multi-meter set to the ohms setting, measure the resistance of
the flammable vapor sensor.
Step 4. Using a multi-meter set to the ohms setting, measure the resistance of
the resettable thermal switch (between the left two pins of the wire harness). The
resistance must be between 3,000 and 48,000 ohms for both the switch and sensor. If
the resistance is out of this range, verify that the resettable thermal switch has not
been tripped. If it hasn’t, replace the thermal switch.
120 VAC Circuit Trace
Step 1. Verify 120VAC and proper polarity are at the wall outlet.
Step 2. With the water heater plugged in and the gas control power switch in the
“ON” position verify LED status.
Dip Tube Inspection and Replacement
Step 1. Move the gas control power switch to the “OFF” position
Step 2. Unplug the water heater from the wall outlet.
Step 3. Turn off the cold water supply to the water heater. Connect a hose to the
drain valve of the water heater and route to an open drain. Open a nearby hot water
faucet to vent the water heater for draining. Open the drain valve of water heater and
allow the water heater to drain to a point below the inlet connection nipple.
Step 4. Disconnect the inlet nipple from the plumbing system.
Step 5. With an appropriate tool, such as a pipe wrench, remove the inlet nipple/
diptube from the water heater. Use caution not to damage pipe threads.
Step 6. Visually inspect the inlet nipple/diptube. The inlet nipple/diptube should
be free of cracks and any blockage. Hydro-jet slots should be open and free of any
blockage.
Any damage, such as cracks, restriction due to deformation, or
unintentional holes are not field repairable and the inlet nipple/diptube must be
replaced.
WARNING
Water heater components and stored water may be HOT when performing the following
steps in this procedure. Take necessary precaution to prevent personal injury.
120 VAC Circuit Trace
28