Hotpoint Washing Machine error code F5 - any advice appreciated

Hi, wonder if anybody can help, I have a Hotpoint washing machine (Ultima WMUD 962P) which suddenly stopped mid cycle and flashed up error code F5. So I googled this and after reading some tips, I took the bottom panel off and drained the machine of water and checked the filter (I did find 2 buttons), I also checked the outlet hose for any blockages, which there wasn't any. I then turned the machine on and attempted to put it on a rinse cycle but nothing happened and it just sounded like the pump out was kicking in. I then tried to put it on a new wash setting and then tried a spin cycle, but whatever setting I put it on, it just makes a noise like it is trying to drain.
Also I have tried putting 2L of water into the drum and running the spin cycle, and still the drum is not turning and the machine just makes a draining sound. Not sure what to try next - any ideas what the issue may be?

Possibly problem with the pressure switch. It will either be fixed to the back of the drum or on top of the drum assembly with a tube running down to the drain pump. A common problem is for these tubes to get blocked usually at the drain pump end. If yours is that type then pull it off the switch & blow down it, You should hear air bubbling in the pump body. If it is fixed to the back of the drum then you need to remove it & check for the water input being blocked. If neither of these apply then check the operation of the switch with a multimeter.