What to Do if Your Dishwasher Salt Cap is Stuck

What to Do If Your Dishwasher Salt Cap Is Stuck

It’s important to tighten your dishwasher’s salt reservoir cap before running a wash. Otherwise, you’ll be spilling salt into your dishes and rendering the salt useless.

If your cap is stuck tight, it’s probably encrusted with salt. You can use a rag soaked in hot water to cover the cap until the hardened salt softens, loosening the cap. Screw the lid back and forth until you can unscrew it completely. You can also purchase a spanner for unscrewing the salt cap.

I’ll now detail different solutions for a stuck salt cap and discuss what a healthy dishwasher’s salt tank should look like. Yes, it should be full of water!


How to Loosen a Dishwasher Salt Cap

How to Loosen a Dishwasher Salt Cap

Dishwasher salt is coarse and thick – much coarser than regular table salt. It also doesn’t contain any anti-caking agents. This means it’s easier for the salt to clump together and harden, which can, unfortunately, happen on the underside of the salt reservoir cap, sealing the cap tight.

You may have also simply screwed the salt cap too tight, making it very hard to unscrew. Try these solutions to unscrew a stuck salt cap!

1. Use hot water

Soak a rag with hot water (not boiling) from the sink and cover the salt cap with it. Leave the rag on top of the cap until it has cooled, then screw the cap back and forth to loosen it.

The hot water should seep into the cap and help the encrusted salt dissolve, allowing you to eventually unscrew the lid.

Try this rag method a couple of times. If it doesn’t work, you can also forgo the rag and pour a little water directly from the kettle onto the salt cap. Let the water cool before attempting to unscrew the cap again.


2. Make sure you’re turning the cap the correct way

turning the dishwasher salt cap the right way

Your problem might be simpler than you think: you’re turning the cap the wrong way, accidentally tightening it instead of loosening it!

Don’t worry, you’re in good company. These Mumsnet users made the same gaffe!

Some caps have an arrow indicating the direction you should turn the cap to remove it. And remember, generally, screw lids clockwise to tighten them and anti-clockwise to loosen them.


3. Use a salt cap spanner

Salt caps can be difficult to unscrew manually and frequently suffer from being sealed with encrusted salt. You want to ensure your cap is sealed tight to avoid spillage but putting in the effort to unscrew it can be tiring.

Fortunately, you can purchase spanners designed specifically for dishwasher salt caps from different dishwasher models.

These handy tools will cost you around £15 and finding the right match is easy—simply check the product description for compatible brands or inspect the picture to see if the lobes match up with those on your salt cap.

This spanner fits the salt caps in Siemens, Bosch, and Neff dishwashers, whereas this spanner is suited to Miele dishwashers alongside other brands.

If your salt cap getting stuck is a regular occurrence, I’d recommend investing in one of these spanners – instead of bringing out the kettle each time you want to refill your dishwasher’s salt.

Customers who have bought the Siemens-compatible spanner are typically thrilled with how quickly and easily it removes their salt cap.

One customer claimed the spanner removed their salt cap which was stuck “as if in concrete”; another explained how they’d tried for weeks to remove their salt cap until trying out this spanner.

The tool is a little expensive for what it is, but I’d say it’s worth it for seamless salt refills.


Why Is There Water in the Dishwasher’s Salt Reservoir?

Water in the Dishwasher’s Salt Reservoir

Unscrewing your salt cap and being faced with a reservoir full of water might make you think your salt cap is faulty and letting water leak into the salt reservoir.

Salt mixes with water in your dishwasher’s salt reservoir to create a salty brine, as part of the water softening process. Leftover water will spill out of the salt reservoir as you fill it with fresh salt; this is totally normal, and nothing is wrong with your dishwasher!

If it’s your first time using the dishwasher’s salt compartment, you’ll first need to fill it to the brim with water. After that, you won’t need to add any water – just salt.



Dishwasher salt caps often become jammed with clusters of salt crystals, making them nearly impossible to remove manually.

Before assuming your salt cap is jammed, first make sure that you’re screwing it in the correct direction!

To loosen your dishwasher’s salt cap, you can cover it with a rag soaked in hot water until the rag cools, then screw the cap back and forth until it’s no longer jammed.

If your salt cap jams regularly, try investing in a salt cap spanner to help you efficiently remove a stuck cap.