Thank you for your purchase! Please start your troubleshooting journey here. We’ll be using a multimeter extensively throughout these guides, so it’s important to become familiar with the meter I’m using, along with the symbols and indicators you’ll see during testing. Understanding these basics will help you follow the diagnostic process more easily and know exactly what to test, where to test it, and how to interpret the readings correctly.
If you're looking for a great maintenance service for your SF style Suburban furnace check this out. The electrode usually also sense flame which makes it critical in the combustion process. If your furnace kicks on for seven seconds and then shuts down this could be your problem. These electrodes build up oxidation which can disrupt the flame sense signal causing the furnace to shut down after 7 seconds of running.
This video shows us replacing a SF-30FQ furnace blower motor. This repair is very similar to many other SF style furnace blower motor replacements so check this out even if it’s not your exact model number. If you have power going to your blower motor and it’s not turning it’s time to replace your furnace motor. Remember the furnace motor will not start its sequence if the sail switch is stuck in the closed position so check proper sail switch functionality and verify voltage out of control board before replacing the motor. The symptom of this failure would be turning on your thermostat to heat but the fan doesn’t kick on.
