Operational Issues And Diagnostics - Dometic DF Series Service Manual

Furnaces

3 OPERATIONAL ISSUES AND DIAGNOSTICS

This section has tables showing the main causes for furnace issues. The Operational Issues table helps you
identify a range of furnace operational issues and the potential servicing solutions associated with those issues.
The Diagnostics table links specific furnace components to the diagnostic tasks associated with that component.
Remember to check the basics before replacing any parts, such as loose wiring and overall heating issues. Refer
to the Maintenance (on page 41)
Review the operational issues table for a list of potential operational issues, possible solutions, and servicing
procedure links. Refer to the
furnace components, for confirmation of the operational issue.
Operational Issues Table
Operational Issue
Motor does not run
Fan motor runs but no spark
Furnace sparks but does not ignite
Motor vibrates or is noisy
Burner ignites then locks out
Furnace is limiting
Fan and burner turn off
EN
and Heating Issues (on page 26)
Diagnostics Table (on page 5)
Potential Reason
Defective motor
Defective external relay
Low DC voltage
Defective circuit board or ignitor on the circuit board
Combustion wheel is loose
Electrode is defective or out of adjustment
Defective limit switch
Defective motor
Defective sail switch
Gas pressure issue
Defective circuit board
Electrode is defective or out of adjustment
Defective gas valve
Orifice issue
Blower wheel is damaged
Blower wheel is dirty
Loose object inside the blower wheel
Motor mount is loose
Motor shaft is damaged
Low gas pressure
Defective circuit board
Combustion wheel is loose
Electrode is defective or out of adjustment
Installation issue
Ducting issue
Return Air issue
Defective limit switch
Defective external relay
sections for more detail.
for links to specific diagnostic information on the
26/see specific furnace installation instructions
26/see specific furnace installation instructions
26/see specific furnace installation instructions
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