Return to Answer

As already noted, that's where the dishwasher salt goes, to soften the water [or more specifically to backwash & refresh the resin bed that does the actual softening]. Without salt the resin will stop working after a few weeks, allowing limescale build-up & a less-effective wash cycle.

Also note that cleaning involves removing the strip seal around the door as well as the obvious filter mechanism in the drainage sump. All sorts of unattractive gunk can get stuck in the seal.

As already noted, that's where the dishwasher salt goes, to soften the water [or more specifically to backwash & refresh the resin bed* that does the actual softening]. Without salt the resin will stop working after a few weeks, allowing limescale build-up & a less-effective wash cycle.

Also note that cleaning involves removing the strip seal around the door as well as the obvious filter mechanism in the drainage sump. All sorts of unattractive gunk can get stuck in the seal.

*See What is Water Softener Resin? (The Only Guide You Need)

Just refilling the salt will not make the smell go away.

Just refilling the salt will not make the smell go away, and in fact the smell is quite pervasive & difficult to shift. It's commonly described as smelling like a wet dog. You are unlikely to remove it in a single cleaning session. It's also likely to be clung to your dish-ware, which will also need more than one wash cycle to de-odour.

The decay & consequent smell isn't starting in the salt reservoir, but if it's not been refreshed in a long time, it could work its way into there, where it will essentially stagnate further. Bear in mind almost nothing can live in a highly concentrated salt solution… but yours is missing. The salt reservoir isn't an area that gets fully flushed through with clean water every time a wash cycle runs, it's little more than a 'drip feed' to the water softener's resin tank, meaning it will stagnate if there's no salt.

Just refilling the salt will not make the smell go away.

The decay & consequent smell isn't starting in the salt reservoir, but if it's not been refreshed in a long time, it could work its way into there, where it will essentially stagnate further. Bear in mind almost nothing can live in a highly concentrated salt solution… but yours is missing. The salt reservoir isn't an area that gets fully flushed through with clean water every time a wash cycle runs, it's little more than a 'drip feed' to the water softener's resin tank, meaning it will stagnate if there's no salt.