The short answer
The useful thing to know about an Upstreman freezer with this symptom is which cause to try first. Here that is Frost built up on the cooling plate, and the one to try last is A sealed-system or compressor fault. Everything near the top of the list is an owner check that costs nothing; the bottom of it is a service call.
What you actually observe
- The cabinet is warm but the unit is clearly running — You can hear the compressor; the air inside is not cold.
- It never switches off — It runs without ever satisfying its thermostat, which is the same fault seen from the other side.
- One part of the cabinet is cold and another is not — That is an airflow pattern rather than a cooling failure.
- NEAR MISS: the unit is silent and nothing is cold at all — That is a no-power or start-relay fault and it belongs on a different page.
Causes, most likely first on this build
- Frost built up on the cooling plate — On a manual-defrost cabinet the cooling plate frosts over in ordinary use, and once the frost is thick it insulates the plate from the air it is meant to be chilling. Ranked first on an Upstreman: a compact cabinet with a manual-defrost chill box collects ice quietly for weeks before the owner notices the warmth.
- A lid or door seal that no longer closes cleanly — A freezer seal has to close against a gasket the whole way round, and a lid that is held off by a frozen crumb or a basket handle leaves a gap all day. Second here, because these units are placed on a desk, a shelf or a carpet rather than installed, so clearance and level are wrong far more often than a part is.
- The room is outside the cabinet's rated band — Every cabinet is rated for a band of room temperatures, and outside that band it cannot reach its set point whatever is right or wrong inside it. Third, once the two above are clean: it costs nothing to rule out and it decides whether anything needs to come apart at all.
- A sealed-system or compressor fault — A refrigerant leak or a failed compressor leaves nothing to carry the heat away. Last, and the reason the order above matters: it is the rarest cause on a small sealed system and the only one an owner cannot touch, so it belongs at the bottom of the list.
Check in this order, and why
- Look at the cooling plate or the freezer compartment for frost — A thick sheet rather than a light dusting names the cause before any tool comes out.
- Close the lid on a strip of paper at several points around it — Where the paper pulls out freely the seal is not closing.
- Find out how warm the room actually gets, not how warm it feels — A room that swings outside the rated band explains the whole complaint without anything being broken.
What an owner can safely check
- Give the cabinet a hand's width of clear air at the back and above it, then run it for a day — Compact cabinets are placed rather than installed, and clearance is the check that is skipped every time.
About 25 min
- Empty the cabinet, switch it off and leave the door open until every trace of frost is gone — No tools.
About 45 min
- STOP HERE if the next step needs a meter on live terminals or any work on the sealed system — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel, because a capacitor can hold a charge after the power is off. Leave the door switch wired exactly as it is: it cuts power to the fan for a reason, and defeating it is never part of a diagnosis.
When to call a technician
Call once the seal, the clearance, the coil and the load are all accounted for and the cabinet still will not hold its band. Call immediately if you smell burning or see oil at the compressor.
Where to go next in this class
What is deliberately not on this page
This page is written for the Upstreman freezer as a class, not for one family or model line. Where a family- or model-specific page exists for your cabinet it is linked above, and it is the more specific answer.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
