Sub-Zero reference · Denver, CO
EC 20 is one defrost cycle in which the freezer coil never warmed and no voltage came back down the feedback wire. Sub-Zero Pro Repair Denver reads that wire before it reads the element — (720) 704-2791.
Sub-Zero Pro Repair Denver — (720) 704-2791
Built-In 600-3 Series, the generation that stores numbered codes
Sub-Zero keeps three entries for one cycle. Code 24 is the under-heat by itself, code 22 the missing feedback by itself, and code 20 is both of them recorded inside a single defrost.
That pairing is why its test list is the longest of the group: six steps, running from the lead through the element and the terminator to the board. We work them in the printed order, because the cheap answers are at the top of it.
A freezer still at its set point with ice creeping over the rear panel
Heat that never reached the coil. The cabinet compensates by running longer, which is why a run-time code often sits beside this one.
Defrost circuit: heater, terminator, thermistor $280–$690
A heater that measures correctly and a code that comes back every cycle
The reporting leg on its own. A terminal backed off at the board, or a joint gone green inside the harness, leaves the element heating and the control none the wiser.
No band covers this one — quoted after the diagnosis
No voltage at the board terminal with a defrost under way
The control side. Everything downstream reads clean, and this is the one answer on the list that is not cheap.
Control board $430–$940
Yes, for now. Nothing in this code touches the cooling itself, so the compartment holds while the coil ices a little further on every missed defrost. What it spends is run time. Book it while it is still a defrost fault.
Where this sits
Bench notes from
Tobias Reinhardt
Checked against
Sub-Zero service manual #7003192 Rev C for the Built-In (600-3) Series: error code table, p. 8-2, and the six-step test list printed against code 20, p. 8-3
Reading it with you
Tell us what the panel is showing and we will tell you what we would measure first. Sub-Zero Pro Repair Denver — (720) 704-2791. On the road 8:00 am – 8:00 pm, seven days.
Describe the symptom on the phone and you will usually hear what it probably is before anyone drives out. A $89 service call covers the visit and the full diagnosis in Denver, and comes off the repair once you approve it.