Service Procedure Ix: Blocked Vent Switch Inspection And Replacement - Bradford White UCG100H3993N Service Manual

Blocked Vent Switch Inspection and Replacement
Blocked Vent Switch Procedure
Step 1. First determine if the "Blocked Vent Switch"
was installed correctly on the drafthood (see
picture right).
Step 2. When Error Code 26 is present you first must
determine if there is a blocked vent condition
present. If so, clear the obstruction and reset
the switch then continue with normal
operation.
Step 3. If the switch is tripped and there is no
obstruction in the venting there could have
been an extended down draft that tripped the
switch. The down draft could have been
caused by damage vent termination. Contact
your plumbing professional to correct this
issue.
Step 4. When no blockage or downdraft issues are present check the continuity of the switch (see photo below). If
there is no continuity present even when switch is reset the blocked vent switch assembly needs to be
replaced.
Step 5. If blocked vent switch assembly is functioning correctly check to see if the wire harness has any signs of
damage. Replace harness if any signs of damage exist.
Step 6. Restore water heater to use and confirm proper operation following the lighting instructions on the lighting
instruction label or the lighting instruction located in the installation and operating instruction manual.
.
Service Procedure IX:
Blocked Vent
Switch should be
installed on the lip
of the drafthood.
Set Voltmeter to Ohms.
The switch should be
very close to 0 Ohms
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