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 5 Flash mean?
Daikin furnace code 5 Flash means the control detected flame while the gas valve should have been off on the supported control family. Confirm the model number and diagnostic chart inside the furnace door before replacing parts.
What causes Daikin code 5 Flash?
- A gas valve leaking or stuck open
- A shorted flame-sensing circuit
- A failed integrated control board
Can I troubleshoot Daikin code 5 Flash?
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 5 Flash 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: DM80HS-style integrated controls using the documented 1–8 flash chart.
- Daikin Comfort Technologies: DM80HS Single-Stage Multi-Speed Gas Furnace — Product Specifications
SS-DM80HS · The 1–8 flash integrated-control family documented for DM80HS-series furnaces; sister-brand models must use the same control chart.
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.