If you’re trying to unlock the Open Backroom Deal achievement in Killing Floor 3, you’ve probably noticed the game doesn’t exactly point you in the right direction. The achievement requires you to destroy a series of hidden electrical boxes scattered around the Onslaught map, and a few of them are surprisingly easy to miss during the chaos of a match.
The good news is that once you know where to look, the achievement is pretty straightforward. Better yet, opening the Backroom isn’t just for completionists—it gives your team access to extra armour, ammunition, and one of the safest spots on the map.
Here’s everything you need to know.
Killing Floor 3 All Electrical Box Locations – Open Backroom Deal
To unlock the Backroom, you need to destroy 10 electrical boxes hidden throughout the Onslaught map.
Every time you successfully destroy one, you’ll notice a material drop. That’s the game’s way of confirming you’ve found the correct box.
After all ten have been destroyed, the Backroom opens, giving your team access to valuable supplies.
Can You Complete It in Any Game Mode?
Yes. The achievement isn’t tied to a specific difficulty or game mode.
You can complete it during either:
- 5-Wave matches
- 10-Wave matches
However, because several areas of the map remain locked at the start, you’ll need to survive long enough for those sections to open. In practice, you’ll need to reach at least Wave 4 before every electrical box becomes accessible.
Why You Should Open the Backroom
Even if you’re not chasing achievements, it’s worth unlocking the Backroom whenever you play Onslaught.
Once opened, you’ll find:
- Extra armour crates
- Additional ammunition supplies
- A safe place for your squad to regroup
One of the biggest advantages is that the Backroom has no enemy spawn points, making it an excellent fallback location when higher difficulties start becoming overwhelming.
If your team needs a breather between Zed waves, this room can make a noticeable difference.
Electrical Box Locations Available Immediately
The first group of electrical boxes can all be destroyed before any of the map’s locked doors open.
Red Tunnel
Check the Red Tunnel area carefully. One electrical box is mounted here and can be destroyed as soon as the match begins.
Catwalk Above the Red Tunnel
Head up to the catwalk overlooking the Red Tunnel. Look along the walls and supports for another electrical box.
Side Room Near Spawn
Before venturing too far, search the small room close to the spawn area. There’s another hidden box tucked inside.
Backroom Tunnel
Near the tunnel leading toward the Backroom, you’ll find another electrical box waiting to be destroyed.
Behind the Trading Pod
Don’t forget to check behind the Trading Pod. It’s an easy location to overlook if you’re focused on fighting enemies between waves.
Locked Electrical Box Locations
The remaining electrical boxes are hidden behind sections of the map that only become accessible as the match progresses.
As new doors unlock throughout later waves, make sure your team explores each newly opened area before rushing to the next objective.
There are five additional electrical boxes located behind these locked sections. Since they can’t be reached immediately, you’ll need to stay alive until those parts of the map become available.
A good strategy is to destroy each new box as soon as a door opens instead of trying to remember them all near the end of the match.
How to Know You’ve Destroyed the Correct Box
Fortunately, the game gives you immediate feedback.
Whenever you destroy one of the required electrical boxes:
- A material drop appears.
- This confirms the box counted toward opening the Backroom.
If you don’t see a material drop, double-check that you’ve actually found one of the required electrical boxes.
The Open Backroom Deal achievement is one of those hidden objectives that’s easy to miss unless you know what you’re looking for. Fortunately, you don’t need to solve any complicated puzzle—you simply need to locate and destroy all 10 electrical boxes scattered throughout the Onslaught map.
Once you’ve opened the Backroom, you’ll gain access to extra supplies and one of the safest locations on the map, making it useful for both achievement hunters and players tackling the tougher difficulty levels. Even if you’ve already earned the achievement, it’s worth unlocking the room in future matches whenever your team could use the extra resources.