HVAC Code Lookup

Ruud Furnace Code 13

Warning

Flame lost after it was established. The burner lit and the control proved flame, then the flame signal disappeared mid-cycle. The control post-purges and retries; five losses in a row send it to a one-hour lockout showing 13 alternating with 10.

Manual wording: “FLAME LOST AFTER ESTABLISHED ... After a successful ignition trial, the flame (which was properly sensed) is no longer sensed.”

Documented for: (-)97V, (-)96V, (-)801S/(-)801P

Likely causes, most common first

  1. The flame sense rod needs cleaning, is not properly connected, or its wiring to the control is shorted or open
  2. An improperly mounted or poorly grounded flame sensor
  3. Flame pattern may be unstable

What you can safely check yourself

  • Check that the burner-compartment door and blower door are fully seated - the manual calls out door and gasket seals as a cause of unstable flame.
  • Check and replace a dirty air filter.

When to call a technician

Flame sensing, burner assembly and heat-exchanger seal checks are all technician work. If code 13 keeps returning, get it diagnosed.

A Ruud furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.

Sources

Other Ruud codes