







At a glance
At a glance
Bosch Series 4 Built-Under Integrated Upright Freezer with NoFrost, 82 x 59.8 cm, flat hinge
A built-under integrated freezer with Total NoFrost, 85 litres over three drawers and a door alarm, sitting behind a furniture front in a standard 60 cm housing.
The GUN21VFE0G is Bosch's Series 4 built-under freezer, designed to sit under a worktop in an 820 by 600 by 550 mm niche behind a kitchen door. It holds 85 litres in three drawers and suits kitchens where the freezer needs to disappear into the run of units rather than stand apart.
Total NoFrost is the reason to choose it. Air humidity is handled automatically, so ice never forms on the walls or on your food and manual defrosting is off the list for good. It also freezes quickly, rated at 8.0 kg of fresh food in 24 hours, and runs at a quiet 35 dB(A).
Ideal For
A flat hinge and a 820 by 600 by 550 mm niche let it sit under the worktop behind a matching door, so the cabinetry runs unbroken across the room.
Total NoFrost stops ice forming inside, which removes the annual job of emptying the freezer, waiting for it to thaw and mopping out the water.
At 35 dB(A) with a class B noise rating, this is one of the quieter freezers to put in a kitchen that doubles as a living space.
Key Features
Frost is prevented from building up inside the cabinet, so the freezer never needs manual defrosting and drawers do not seize up over the winter.
Frozen storage is divided across three drawers, giving 85 litres in total within a standard under counter footprint of 82 by 59.8 cm.
Bosch rates it at 8.0 kg of fresh food frozen in 24 hours, which is generous for a freezer of this size.
Switch it on before adding a big shop and the cabinet chills down first, protecting food that is already frozen from partial thawing.
An LED display shows status and warns you if the door has been left ajar or the internal temperature has risen, before food is affected.
The inside is lit by LED, so the contents of all three drawers are visible even when the freezer sits low under a worktop.
What Total NoFrost actually changes
Frost builds up in a conventional freezer every time moist air meets cold surfaces, and eventually you have to empty everything out and defrost the cabinet. Total NoFrost prevents that build-up entirely, so drawers keep sliding freely, packaging stays legible and the usable space does not shrink as ice creeps in. It is the single biggest quality of life difference between this Series 4 and a cheaper static freezer. Bosch rates the appliance at 189 kWh a year, class E on the current label.
Fitting it under the worktop
This is a built-under appliance with a flat hinge, which means the furniture door is fixed directly to the freezer door and opens with it. It needs a niche of 820 mm high, 600 mm wide and 550 mm deep, and the appliance itself measures 82 by 59.8 by 54.8 cm. The hinge is right hand as supplied and can be reversed. Bosch also offers a stainless steel attachment door, reference KUZ20SX0, if you would rather not use a kitchen panel.
Freezing quickly and quietly
A freezing capacity of 8.0 kg in 24 hours is high for a cabinet of 85 litres, so a bulk shop or a session of batch cooking freezes through properly rather than slowly. SuperFreezing lowers the temperature first when you know a lot is going in. Day to day the freezer runs at 35 dB(A), a class B noise rating, and if the door is left open or the temperature rises the LED display tells you. Frozen food stays safe for nine hours if the power goes off.
How It Compares
| Kitchen Need | Bosch Technology | Practical Benefit |
|---|---|---|
| Fitted kitchen run | Built-under flat hinge | The furniture door mounts straight onto the appliance, so the freezer disappears into the line of base units. |
| Defrosting day | Total NoFrost | Ice is prevented from forming inside, so the yearly ritual of emptying and thawing the freezer never comes round. |
| Bulk buying | 8 kg freezing capacity | Up to 8.0 kg of fresh food can be frozen in 24 hours, so a large shop is handled in one go. |
| Open-plan kitchen noise | 35 dB(A) operation | A class B noise rating keeps the freezer quiet enough not to intrude on a kitchen that doubles as a living room. |
| Forgetful households | Door open alarm | A warning is raised if the door is left ajar or the temperature rises, before the contents start to suffer. |
| Storing a big shop | Three freezer drawers | 85 litres divided into three drawers keeps meat, vegetables and ready meals separated instead of stacked in one heap. |
Specifications
| Brand | Bosch |
| Model | GUN21VFE0G |
| Product Type | Built-Under Integrated Freezer |
| Series | Series 4 |
| Freezer Capacity | 85 litres |
| Energy Rating | E |
| Energy Consumption | 189 kWh per year |
| Star Rating | 4 star |
| Freezing Capacity | 8.0 kg in 24 hours |
| Storage Time in Power Failure | 9 h |
| Noise Level | 35 dB(A) re 1pW (noise class B) |
| Defrosting | Total NoFrost - fully automatic, no manual defrosting |
| Drawers | 3 freezer drawers, 0 freezing flaps |
| Features | SuperFreezing, LED interior light, LED indication display, door open alarm and temperature rise warning |
| Door Hinge | Right, reversible - flat hinge (fixed door, takes a furniture front) |
| Climate Class | Extended temperate, temperate, subtropical, tropical |
| Connectivity | No Home Connect |
| Dimensions (H x W x D) | 82.0 x 59.8 x 54.8 cm |
| Niche Size (H x W x D) | 820 x 600 x 550 mm |
| Weight | 30.3 kg |
| Power Cord Length | 230 cm |
| Optional Accessory | KUZ20SX0 stainless steel attachment door |
| Warranty | 2 Year Warranty |
The Verdict
Strengths
- Total NoFrost removes manual defrosting entirely
- 85 litres across three freezer drawers
- Freezes up to 8.0 kg in 24 hours
- Quiet 35 dB(A) running, noise class B
- LED interior light and LED status display
- Door open and temperature rise warnings
- Reversible flat hinge for a fitted furniture front
Considerations
- This is a built-under integrated appliance, so it needs an 820 by 600 by 550 mm niche and a furniture door fitted by an installer.
- Frozen food stays safe for only nine hours in a power cut, less than some static freezers of comparable size.
- There is no Home Connect on this model, so temperature and alarms can only be checked at the appliance itself.
What's in the Box
- Built-under freezer x1
- Ice cube tray x1
- Installation/user manual x1
Compare Similar Models

| Specification | Bosch Series 4 Built-Under Freezer NoFrost 60cm | NEFF N50 Built-Under NoFrost Freezer - White | Bosch Series 4 Built-In Under Counter Freezer 56cm | Bosch Series 4 Freestanding Frost Free Freezer 186cm - White |
|---|
At a glance
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Energy efficiency
- Energy Consumption189 kWh per year
- Noise Level35 dB(A) re 1pW (noise class B)
Why you’ll love it
A built-under integrated freezer with Total NoFrost, 85 litres over three drawers and a door alarm, sitting behind a furniture front in a standard 60 cm housing.
- Total NoFrost removes manual defrosting entirely
- 85 litres across three freezer drawers
- Freezes up to 8.0 kg in 24 hours
- Quiet 35 dB(A) running, noise class B
- LED interior light and LED status display



