NEFF Dishwasher problem with 50 and 65deg cycle

[s1ilverback]

Right - here goes - first time post so apologies for the length of post, hopefully the more detail the better

I have an 8 year old NEFF Built in dishwasher model S5443X2GB/42.

It has been used very infrequently (maybe once every 2 months) in its lifetime.

Recently we have noticed on the 50 and 65 deg cycle the machine will wash for about 45mins to an hour then appear to get stuck in a cycle of attempting to drain, but never actually doing so.

We have let this run for up to 4 hours with no apparent moving on from this behaviour. When i open the door, there is water sitting at the bottom of the unit and the strange thing is that if i hit the two buttons to reset, and close the door, the machine drains completely.

I dont beleive the 35 deg wash is affected, however i dont really have something to compare it against, it appears to run to completion, the water is warm and the cycle only lasts about 40 minutes.

Havnig read some other posts, i saw a description of how to enter the test options - by closing the soap drawer holding down two buttons and powering the machine on. the following are my findings:

I always held down the 50 and 35 deg buttons on powering on (and the 50 deg led is on and the 35 led is flashing after powering on)

After powering on

1. I Press the 65 deg button, the 65 and 50 deg leds flash together
or
2. Power on and press the 50 deg button, the 35 deg led stays lit
or
3. Power on and press the 35 deg button, the 65 deg led flashes slightly quicker
or
4. Power on and pressing rinse button just keeps 50 led on and 35 led flashing.

Any advice greatly appreciated

 

[s1ilverback]

ok - further update:

i am getting a "filler fault" on the test cycle. i suspected a falt with the pressure chamber and purchased a new one which is now fitted, but alas to no avail.

having looked at the relevant manual, i notice that the 35 deg wash goes straight into the wash cycle whereas every other program does a pre-rinse first - could this be the issue?

any advice?