ICP Furnace Showing 80% Limit Fault
December 8, 2025
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Most gas furnaces have several safety limits, main limits, roll-outs, 80%’s will have a DSS (Daft Safety Switch) These safety
VRF Quality Assurance Manager
Gulf Coast District
Historically, any dipswitch on a Carrier/Bryant mini split outdoor PC board were set by the factory and left alone. Now, for many of the outdoor units there are universal replacements. This PBA (Primary Board Assembly) Inverter will cover almost the entire ensemble of Carrier/Bryant ductless 9,000 and 12,000 Btu heat pumps and air conditioners. It makes a difference how you set the dipswitches
A DC fan motor will have only 3 wires and no capacitor. An AC motor will have 5 wires (3 to the motor and 2 to the capacitor). The universal PBA comes with an adapter plug and new capacitor for AC voltage motors. The plug locations on the board are specific to each motor. There are 2 dipswitches labeled SW2 for whichever one you have. In North America: for DC fan motors, both bit 1 and 2 should be off. For AC both bits should be on.
I vote easy! Use your handy dandy service tech app. Any version will do…
Find the service literature for your specific outdoor unit. The compressor model numbers, and ohm values are published in every service manual for these units. Match your numbers to the chart provided on the back of the PBA and table below.
Or, if you prefer the hard way, just check the numbers on the compressor. Unfortunately, the model tags are facing the inside of the unit. You can try to get your camera phone in there and get a photo or use your mirror from your torch set and a flashlight to see back there and verify the model. Then set the SW1 dipswitches accordingly. See table below.
Everything else should be plug and play!
Take photos or good mental notes of the CN#(s) on each connector.
Some connectors can fit in places they don’t belong. However, they are color for color.
Disclaimer: The technical statements, information and recommendations contained herein are believed to be accurate as of the date hereof, but Mingledorff’s does not make representations or warranties, express or implied, as to its accuracy, its completeness, or the results to be obtained. The information is being provided for informational purposes only and is intended for use by persons having adequate skill and expertise regarding the proper selection, use and application of the products and recommendations and at their own risk and discretion.
Most gas furnaces have several safety limits, main limits, roll-outs, 80%’s will have a DSS (Daft Safety Switch) These safety
This article is in reference to Residential Heat Pumps. Everyone in the HVAC industry knows that the indoor TXV
Compressors are the heart of the refrigeration system. It creates the pressure difference to move the refrigerant through the system.