Written by
Lena Hartwell Appliance Care EditorPublished October 27, 2026
VERIFIED
Error codeC-21
ApplianceWall Oven
Meaning of C-21
C-21 is the information code for an abnormally high internal temperature. It is in the manuals for the DOC30*977D* combi oven, the Modernist DOB30M977 wall oven and the Modernist Pro DOP36M86D and DOP48M86D ranges.
Steps
Modernist Pro range manual: restart the appliance.
Wall oven and combi oven manuals: no step is listed.
Should C-21 return after a restart, request service.
C-31 reports abnormally high PCB temperature, with call for service as the manual instruction.
C-A2 reports the cooling motor behaving abnormally.
Dacor oven repair around San Francisco
If C-21 comes back on a Dacor oven in San Francisco after you restart it, read about Dacor wall oven repair and call (415) 687-5926. Please have the model number and the code ready.
Model compatibility: Dacor reuses codes across series and model years, so C-21 may mean something different on another appliance or generation. Confirm this against your model’s documentation and record your full model number before acting.
Plain language
What this code means
C-21 means the internal temperature is abnormally high.
Important safety warning. Do not attempt repairs involving electrical components, gas, water lines, refrigerant or sealed systems. Unplug the appliance if it is safe to reach the outlet, and leave internal diagnostics to a qualified technician.
Seeing this code on your Dacor appliance?
Book a specialist visit for a clear estimate and approval before any repair.
You submit a request with your appliance model and symptom, we confirm an appointment window, and a technician performs an on-site diagnosis. You then receive a clear estimate and decide whether to proceed before any repair begins.
Yes. We provide an upfront estimate after diagnosis. No parts are ordered or installed until you approve the work, so there are no surprise charges.
Replacement parts are selected for the exact model and confirmed with you before ordering or installation.
Service areas are listed on the Locations page. Contact us with your ZIP code to confirm current coverage for your address.
Ready to get your Dacor appliance working again?
Book a repair online or call us — clear estimates and approval before any repair work begins.
