Bosch Exxcel DW dispensing detergent during prewash?!

[iej]

I've a mid range Bosch dishwasher that's getting to to about 5-7 years old (I've lost track) it's still similar to the current machines.

I usually use the "Auto Daily" sensor cycle but when I used intensive I noticed I got poor results.
Checked the filters, spray arms and nothing was blocked.

Then I ran a cycle again and noticed it opened the detergent dispenser mid way through the hot prewash.

It half dissolved the Finish tablet in the holder on the top rack. Then emptied (dumping most of the detergent) and continued into the main wash without detergent!

Seems an odd fault to suddenly develop because it looks more like software issues than mechanics!

Any ideas?[this post was last edited: 10/24/2015-06:45]

 

[rolls_rapide]

I wonder if the electronics module is losing its mind?

My mum had a Hotpoint dishwasher FDW20 (Indesit origin) that forgot where it was in the cycle, leading to a poor wash and dripping dishes.

 

[yoblount]

detergent door

Is it possible that the detergent door was not fully latched? Have you noticed this happen again since your post on the 24th?

 

[richnz]

My auto cycle

is inclined to skip the prewash.

However I don't have poor washing results.

Would a tablespoon or two of cocoa convince it to not skip the prewash?
Are prewash cycles normally heated also?

 

[iej]

I'll check it out later today. I haven't had a chance to monitor it since.
The auto cycle is working fine. It was the intensive cycle this happened in.

All cycles on this machine seem to come with a heated prewash. It only uses a tiny amount of water anyway so, I doubt it's a big deal in terms of energy.