The error code E10 on a Hotpoint dishwasher refers to a time out for either fill or empty. The wash cycle’s program control allows a set time to fill. After this time if it hasn’t received the signal that the dishwasher has filled up with the right level of water it will time out and display E10. Conversely if it times out on draining and there’s no signal that the dishwasher has emptied all the water properly the same error is called.
If it is displaying the error at the beginning of the wash cycle and you suspect it is fill related you could try to check that the fill hose taps are turned on properly (it’s more common than you think). Also check there is a supply of water at a decent pressure going through the hose (faulty taps can appear to be on, but furred up inside so that little or no water is getting through. This is particularly common on DIY self-tapping taps with hot taps most likely to be affected. Also, check that there is no kink in the fill hose (unlikely unless the dishwasher has been moved within the last few months or recently installed)
If the dishwasher isn’t emptying the water properly there could be a pump fault, connection fault or a blockage (often glass) in the pump.
I wouldn’t advise getting too involved with diy dishwasher repairs as they are often very difficult to work on and access to parts is very hard because of the way they are designed.
I’ve written some general tips and advice for washing machines that won’t fill or drain, which may be useful here too Washing machine won’t fill with water (or no water goes into washing machine) | Won’t drain water
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