LG WM1460FHD problem

Hi,
went to an LG WM1460FHD last week with a “IE” fault code – lack of water I believe. It seemed to be slow filling so I changed to dual cold valve. Filled much better after that. Job done I thought. However, customer (it’s in a hairdresser’s shop and is on several times a day) phoned in the week to tell me that it works for about 3 washes, then “IE”, then works ok for another few washes, then “IE” again. Went back to it yesterday, and on test, I feel that it’s just not taking in enough water. Good flow into the machine though. Pressure chamber and pipework all clear. Does this machine have a normal pressure switch or is it some kind of pressure sensor? Cos when I blow into it, there’s no click. When I actually watched the machine yesterday, it filled for about 15 seconds then started it’s wash action. After about 10 minutes, “CL” flashed up, but the wash kept going. After a further 2 minutes or so, it aborted with “IE” and started beeping. I’m not over familiar with these machines so any help will be gratefully received.

Here’s hoping,

Dave