Vent Safety Switch Testing And Replacement - Bradford White eF Series Troubleshooting Manual And Instructions For Service

Vent Safety Switch Testing and Replacement

WARNING
120 volt potential exposure. Isolate the
appliance and reconfirm power is
disconnected using a multimeter.
Sequence of Operation
For Hot Surface Ignition models: With the thermostat calling for heat, prior to energizing blower, the ignition module
checks the vent safety switch for normal switch position of normally closed. If the vent safety switch contacts are open,
(not in normal position), the ignition module waits indefinitely for contact to close. The vent safety switch must be
manually reset to close the switch contacts.
For Integrated Control models: Error code 26 will display indicating an open circuit for the vent safety switch.
Determine if temperature has reached 350°F before resetting switch and restoring operation. If evidence of extreme
temperature is present, call Technical Support.
For ICON System models: Error code 67 will display indicating an open circuit for the vent safety switch. Determine if
temperature has reached 350°F before resetting switch and restoring operation. If evidence of extreme temperature is
present, call Technical Support.
Locate harness connection
(see image at right).
Replace vent
safety switch
(see Vent
Safety Switch
Replacement
Procedure,
pg 47).
Service Procedure XI
Is there continuity through the
gray lead wires of heater side
harness? (see image below)
Depress reset
Y
button on high
limit switch. Is
N
there continuity
across high limit
switch? (see
image below)
WARNING
Make sure the exhaust collector compartment is not
overheating (350°F) before resetting vent safety switch. If
there is evidence the collector compartment is
overheating, call Technical Support.
Reset heater.
Y
Observe the
heating cycle.
Does the
switch open?
Y
Does the
heater
Does the switch
function?
open prior to
N
Call Technical
Support.
Replace vent safety
switch (see Vent
Switch Replacement
Procedure, pg 47).
System O.K.
Y
N
Is temp over
350°F?
Y
DO NOT
N
OPERATE
HEATER!
350°F?
System over
heating,
Y
immediately
contact
Technical
Support.
Safety
N
47
47