Display shows E16, furnace may lock out after several failed attempts to modulate.
Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
Possible Causes
How to Fix / Troubleshooting
Safety: Turn off power and gas. Gas valve work must be done by licensed personnel.
- Inspect modulation connector: Locate the modulating gas valve on the Termet gas train. Check the low-voltage modulation connector for tightness and corrosion.
- Check wiring harness: Follow the harness back to the control board. Ensure there are no cuts or pinched sections.
- Reset the unit: Restore power and gas, then reset the furnace. Observe if the burner lights but cannot modulate before E16 appears.
Important: Do not attempt to adjust or replace the gas valve yourself. A Termet-certified gas technician must verify gas pressures, valve operation, and combustion settings.
Repair Difficulty
Required Part
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