Hi Jo,
Had exactly the same problem with a WD640, which I've just fixed.
I also initially went through lowering the water pressure to the point that it was taking ages to initially fill up; however, still ended up flooding the kitchen out of the detergent dispenser. The problem is not the water pressure, it's that the washer can't pump the water out fast enough - it my case this was due to a couple of my daughters little socks!
If your Hotpoint washer is a similar design to mine, you'll not have a user-accessible pump filter, so - presuming you're happy doing it and the machine is unplugged from the electricity of course - I rectified by the following:
1. Switched the machine to 'pump-out' and got rid of as much water as possible.
2. Unplugged and disconnected the pump-out pipe from the house drainage and drained off as much additional water as possible into a bowl by gravity.
3. Removed the panel at the bottom of the back of the washer to expose the pump, the bottom of the drum and the main washer motor.
4. On the right-hand side, you'll see the pump with the grey (in my case) drain pipe and a wide black rubber pipe connected directly to the bottom of the drum by an adjustable metal clip
5. The wide black pipe attached to the drum contains a ball-filter and is probably the source of your problems - undo the clip (watching for water of course; though none was spilt when I did it) - and lower it slightly to reveal the filter and - hopefully - the odd sock or so!
6. Clear the filter of the obstructions (the plastic ball can be lifted out by the way to aid doing this)
7. Make sure the ball is back in place and connect the wide black pipe back up to the bottom of the drum - ensure the clip is secure
8. Replace the machines back panel
9. Connect the drain pipe back up to the house drainage
10. Do a test wash !
Hope that helps - in practice it took about 10 minutes all together and is pretty easy.
cheers,
John
John, March 2006