Carrier furnace Status code 11: No previous code stored
Code 11 means the control has no fault stored. It is the answer you get when nothing has gone wrong recently, and it is also what a recently power-cycled furnace reports even if something did.
Applies to: Carrier 58MCB four-way multipoise condensing gas furnaces and related models using the same integrated furnace control. Bryant and Payne furnaces of the same generation use the same control and code set.
What it means
Carrier's status codes are two-digit numbers displayed as short flashes for the first digit and long flashes for the second, so code 11 is one short flash followed by one long flash. It means no previous code is stored. Two details make that more useful than it sounds. Stored codes erase automatically after 72 hours, so a fault from last week leaves no trace. And on red LED boards, stored codes are also erased whenever power to the control is interrupted — which means switching the furnace off and on before reading the code destroys the very information you were about to look up.
Most common causes
- Nothing has faulted within the last 72 hours. This is the normal reading on a healthy furnace.
- The fault occurred more than 72 hours ago and has aged out of storage.
- Power to the control was interrupted, clearing stored codes on a red LED board.
- The furnace was switched off and on before the code was read.
- The breaker was reset, or a power cut occurred, between the fault and the reading.
How to diagnose it
- Read this code in context. On a furnace that is working, it confirms nothing is stored. On a furnace that just failed, it usually means the evidence was erased.
- Avoid cycling power before reading codes. If a furnace has faulted, read the display first and reset second.
- If the furnace is failing intermittently, watch for the fault to occur and read the code within 72 hours.
- Note that a component test sequence displays code 11 four times at its start, which is normal and not a fault.
How to fix it
- Nothing to fix if the furnace is running correctly.
- If the furnace has a problem and shows code 11, wait for the fault to recur and read the code before touching the power.
- Record the code when you see it. Writing down the flash pattern at the time is more reliable than trying to recover it later.
- For an intermittent fault, note the date and time it occurred as well as the code, since that helps a technician correlate it with weather or usage.
Notes
The instinct when a furnace stops is to switch it off and on. On these Carrier boards that is exactly what destroys the stored fault code. Reading the display before resetting costs nothing and often saves a return visit.