Dishwasher using too much salt

[Millwright]

A Zanussi ZDT21006FA dishwasher is going through salt. I can fill the sump up and it'll be gone in days. I've inspected the cap and gasket, cleaned it all out but usage is still high. Any suggestions?

 

[foxhole]

Usually adjustable setting for salt usage in DW.? What is yours set at ?

 

[Millwright]

It's set fine, it hasn't been adjusted, it's been fine for years until the last few months.

 

[foxhole]

A dirty DW uses a lot of salt , run a cleaning cycle , salt container may be cracked , when opening the salt cap a little water should escape ( the container is under pressure in use ) if this doesn’t happen it could indicate a damaged salt unit.
There is also a solenoid to allow water into salt unit that could fail and remain open .

 

[Millwright]

We'll see what happens next, I've given it a good clean. Checked the salt lid and it doesn't appear contaminated to suggest that the lid is leaking......

I've really only just noticed this issue. This is my partners dishwasher. My own one at my place is a Bosch and I can throw anything at that and it doesn't want a salt refill for months on end, so perhaps there is the solenoid issue.

So I'll need to find a service manual and get checking as it's getting tiresome filling it with salt every week, but we'll see if the clean has helped.

 

[Millwright]

Salt empty again!

I'm going to need to find out what I need to know about this dishwasher as this is simply quite frustrating!

 

[foxhole]

Salt empty again!

I'm going to need to find out what I need to know about this dishwasher as this is simply quite frustrating!

Lots of YouTube videos showing how to repair white goods.

 

[Millwright]

Thanks.

I've had a quick look, is this it, circled? I've unplugged it as you can see, need to see what I've got to draw the water out of the reservoir

 

[Millwright]

Assuming that is it, which I think it is as it's on the salt reservoir, I've had the valve out.

It appears normally closed, with a plunger going into an inner pipe. So I'm imagining that when the coil is energised, the plunger comes back, allowing water to flow? The plunger doesn't appear to be stuck back, so I'm not seeing that it is stuck open, unless I'm not understanding the operation.

I haven't got anything here to test the solenoid, I'll have to bring something home from work or take it to work, as I'd like to energise the coil and see that the plunger moves, or not. I've measured the coil at 3.5k ohms.

 

[Millwright]

One of the appliance videos suggested that the solenoid plunger can get stuck, so perhaps that's what's happened.

I gave the solenoid plunger, spring and the bore a good clean, put it all back, but didn't connect it.

I then filled the salt reservoir with some salt, enough for the light to go out. I'm monitoring the level with the valve not in operation, seeing that it remains closed off sufficiently.