Flame Sensor Service Tip

One of the most important things to remember is that when you're working on a furnace, you can’t service the equipment effectively & efficiently without having a way to read flame sense. The time is far past when all you needed to service a furnace was an AC/DC volt meter. A meter that reads DC microamps will let you know what the flame sense is. You should have a reading of between 2 and 4 microamps, but it can be as high as 7. Corrective action should be taken with a reading below 2 microamps.
If you have a low microamp reading you can clean the flame sensor with steel wool (do not use sand paper). If you can’t improve the reading by cleaning, replace the flame sensor.

If you still can’t get a decent reading you probably have a problem with grounding or the position of the sensor in the flame. If you're a contractor servicing the equipment, you may need to contact your local distributor or the manufacturer directly. If you're the homeowner, it's always recommended to contact a trusted, local contractor to come and service or diagnose the equipment.

To get a good reading on DC microamps, you need a good tool to do it. Here at ComfortGurus.com, we recommend the Supco CPH100 HVAC/R Current Sensing Probe, which is affordable and takes care of your microamps reading, as well as the following.

Features/Benefits of the Supco CPH100:

• 400 Amps AC
• DC µAmps
• AC/DC Volts
• Resistance
• Capacitance
• Temperature
• Frequency
• Continuity
• Auto Shut off
• 1 year Warranty
• Includes Test Leads

Applications of the Supco CPH100:

• HVAC Equipment Consumption
• Flame Safeguard circuits (CPH100)
• Branch Circuit Current
• AC Line and Control Voltages
• Continuity Check
• Temperature Testing
• Capacitor Testing

Where to Buy the Supco CHP100:

• Purchase at ComfortGurus.com here