Not cooling · Which part of it is warm?
One Section Died and the Other Is Perfect. How?
- Signed
- Dean Halvorsen
- Role
- Refrigeration technician — sealed systems and airflow
- Certification
- EPA Section 608 certified
- Published
Short answer
Your built-in combination gives each section a compressor and refrigerant of its own, and one of them has stopped. Check that the dead section was not switched off by itself at the control; if not, suspect power to that compressor, its start parts or the compressor. Sub-Zero Repair Edmonds measures each for the $89 service call: (206) 210-3547.
Dual refrigeration, in plain words
Sub-Zero calls it dual refrigeration. On its built-in combinations the fridge and the freezer each get a compressor (the pump that drives the refrigerant round), coils of their own and a charge of refrigerant sealed in with them. The serial tag, as Sub-Zero’s service manual lays it out, lists the two charges separately. No refrigerant passes between the sections, which is how one can stop cold while the other carries on untouched.
Room temperature is a different clue
A section running a few degrees high usually points at a fan, a seal or frost. A section that has gone all the way to room temperature suggests its compressor is not running at all, and there are only a few reasons for that:
- The section was switched off by itself. One section can be disabled at the control while the other keeps running, and Sub-Zero’s own troubleshooting page asks owners to rule that out first when one side has no cooling and the other works normally.
- No power from the control. Sub-Zero’s service manual lists a power-to-compressor fault and traces it back to the control board.
- Start parts or wiring. The relay and overload protector (the small parts that get the motor turning and cut it off if it overheats) can fail, and so can the wires to them.
- The compressor itself, seized or with a failed motor winding.
A compressor can also run while that side’s refrigerant has leaked away; the gauges show that.
How a technician proves which one
Voltage is measured at the silent compressor while the control is calling for cold, and at the start, because a low supply makes the start drag on until the overload trips. The start parts are tested next, then the motor windings: resistance is read between the compressor’s terminals and from each terminal to ground. Gauges come after all of that, and if a compressor does go in, Sub-Zero’s service manual has the filter-drier (the small canister that traps moisture) replaced with it.
What it may cost
$89 to find out — the visit and the diagnosis, taken off the repair if you go ahead.
- Compressor or sealed-system repair Shows as a compressor that clicks and will not start, or refrigerant slowly lost $1,300–$3,270
- Electronic control board Shows as a lit display and working lights while nothing calls the compressor on $420–$880
Start parts and wiring sit outside the sealed system, so they are priced after the diagnosis rather than from either range above.
Ranges, not starting prices. The technician names one figure inside the band before any panel comes off, and Sub-Zero Repair Edmonds holds to it.
Wait or call today?
Can wait until morning
- The working section is at its usual reading: move what fits into it, keep both doors closed and book a visit.
- The section that died held only drinks or spare stock that can wait in a cooler with ice overnight.
Call today if
- The dead section is a full freezer. The FDA gives a full freezer about 48 hours with the door shut, and that time is already running.
- Something in the base clicks every few minutes and the dead section never starts.
- The section that was fine has begun to warm too.
Anything in the second card is a reason to phone Sub-Zero Repair Edmonds on (206) 210-3547 today rather than tomorrow.
Questions people ask next
Is it safe to keep using the half that still works?
Yes. The working section cools with its own compressor and refrigerant, and it does not rely on the dead side. Keep a thermometer on a middle shelf and use it as normal while it holds its reading. Sub-Zero Repair Edmonds can test the other side for the $89 service call; ring (206) 210-3547.
Does one dead compressor mean the whole unit is finished?
No. Only the failed section needs work, and what that work is decides the cost: a start part or a control output is a far smaller job than a compressor. Whether a compressor is worth replacing depends on the rest of the unit, which this site's repair-or-replace questions take step by step.