Not cooling · Is the refrigerant going?
It Got a New Compressor and It Is Still Warm. Why?
- Signed
- Dean Halvorsen
- Role
- Refrigeration technician — sealed systems and airflow
- Certification
- EPA Section 608 certified
- Published
Short answer
First give it time: Sub-Zero allows 24 hours for a unit that has been off to cool properly. If it is still warm after that, either the old compressor was not the whole fault, or part of the job needs another look — the charge, moisture, a blockage or a new joint leaking. Sub-Zero Repair Edmonds can check it: (206) 210-3547.
Let it finish cooling down
After sealed-system work the cabinet starts from warm, and Sub-Zero’s normal operating pressures describe a unit running steadily, not one still pulling down. Read it with a thermometer standing in a glass of water — Sub-Zero’s method allows 12 hours for the glass itself to settle — and judge the unit only after the full 24 hours; the display shows the setting, not the shelves.
Still warm the next day: two kinds of cause
The compressor was not the whole story. A fan that has stopped, ice choking the coil after a defrost failure, or a control that never powers the compressor will keep a unit warm whatever compressor is fitted. A leak matters most: running short of refrigerant works a compressor harder and hotter, so it may have worn out the old one and still be there.
Something in the job needs a second look. For a compressor change, Sub-Zero’s service manuals list: capture the refrigerant, replace the compressor, fit a new filter-drier (a small filter that holds back moisture), clear the system of air and moisture, and recharge. After a burn-out the manuals add flushing and extra drying. Too little or too much refrigerant, moisture left inside, a blockage or a new joint that leaks can each leave it warm.
The pressures tell these apart: in Sub-Zero’s manuals, low on both sides suggests a leak, low on the coil side with high on the condenser side a restriction, and high on both an overcharge.
Who to call first
If another company fitted it, contact them first — the work is theirs. For an independent reading, Sub-Zero Repair Edmonds can measure the system and tell you what it shows.
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
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 unit was restarted within the last day and the thermometer is still dropping.
- The food is somewhere cold for now and the reading keeps falling, however slowly.
Call today if
- A full day has passed since the restart and the fridge still reads above 40°F.
- The new compressor clicks on and off without running, or cycles while very hot.
- There is an oily mark where the tubing was newly joined.
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
How long should it take to cool after a compressor replacement?
Give it a full day. Sub-Zero asks that a unit which has not been running is left on for 24 hours before its temperatures are judged, and the cabinet, shelves and insulation all start near room temperature. Check it with a thermometer sitting in a glass of water at the centre of the compartment rather than trusting the display.
Can the new compressor itself be faulty?
It can, though it is rarely the first suspect. A replacement gets the same tests as the old one: power at its terminals, the start parts, the windings measured, then pressures once it runs. If those are sound, the answer lies in the charge or elsewhere in the system. Call Sub-Zero Repair Edmonds on (206) 210-3547 to have it measured.