Turn the furnace off and do not reset it. If you smell gas, leave the building without operating switches and contact the gas utility or emergency services from outside.
What does Daikin code E4 mean?
Daikin furnace code E4 means the control detected flame when no flame should have been present on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Daikin code E4?
- A gas valve leaking or stuck open
- A shorted flame-sensing circuit
- A failed integrated control board
Can I troubleshoot Daikin code E4?
Turn the furnace off and do not reset it. If you smell gas, leave the building without operating switches and contact the gas utility or emergency services from outside.
How much does Daikin code E4 cost to fix?
A gas valve replacement typically costs between $300 and $1,000 nationally.
When should I call a technician?
Turn the furnace off and call a licensed technician immediately to test the gas valve and flame-proving circuit.
Sources and model scope
Fault codes vary by model and control board. Confirm the diagnostic chart inside your furnace panel or the official manual before acting.
Scope used here: AR9S/GR9S and matching Daikin DR-series single-stage controls that display this E-code.
- Goodman Manufacturing: Service and Troubleshooting
RS6621301 · Goodman/Amana AR9S and GR9S, and Daikin DR-series single-stage furnace controls; use only for the E-code entries explicitly listed in the manual.
Compiled by Warmlo Editorial · Reviewed August 2026
This is general information, not professional advice. Gas, electrical, and combustion repairs can be dangerous — when in doubt, call a licensed technician.