HVACopediaICP · Furnace
3+5 Gas valve fault (modulating valve)
What the control is telling you
The modulating gas valve did not answer a command from the control, or power to the valve electronics was interrupted.
Applies to: ICP F9MAE / G9MAE modulating variable-speed condensing gas furnaces (060, 080, 100, 120 kBtu/h)
Likely causes
- Intermittent RED, YELLOW or ORANGE wire at the gas valve
- Loose PL8 connection
- Failed modulating gas valve or control
Test and repair steps
- Warning: Turn power off before checking connectors.
- Check RED, YELLOW and ORANGE wires and terminals at the gas valve and PL8.
- Run component self-test (SW1-6) - the control tests communication with the gas valve.
- If wiring is good and the code repeats, replace the gas valve or control (manual text is cut off here - check the service label).
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Source: ICP (F/G)9MAE Service and Technical Support Manual 440 04 4700 00, Figure 16 Troubleshooting Chart, p.34. Summarized in our own words; check the original manual for your model.
Homeowner looking at this code? See what it means for you and when to call a technician.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.