Hotpoint FDW60 error 4&6

Hi,

Hotpoint Aquarius FDW60P dishwasher.

Problem –
Intensive (65′) cycle (prewash, wash, rinse, dry) – takes in water, heats OK, prewashes, empties, ‘click’, stops with error 4&6.
Eco (45′) cycle ((prewash, wash, rinse, dry) – takes in water (t/w), heats OK (h), prewashes, empties, t/w, h, washes (several times), empties, t/w, h, rinses (several times), empties, stops with error 4&6 but dries with residual heat in the machine.
We live on a remote Greek island (problem ‘just’ getting spare parts).

Tried so far –
all filters cleared/cleaned.
run empty with vinegar to flush through pipes (YUK).
dismantled machine, cleaned through all pipes and heater, fixed leak from circulation pump (still working OK), cleaned water inlet device and flow meter (filthy!!!), cleaned rinse aid dispenser, cleaned salt dispenser, checked (visually) main PCB both sides.
read multiple webpages online.
banging head against wall.
pulling out hair.

Not tried so far –
testing thermistor (don’t know the temperature/resistance readings for this particular item).
pressure sensor (but as it works OK on Eco cycle this wouldn’t seem relevant).
contacting Hotpoint (tried that in the past; used to be VERY good, past 5years USELESS (see footnote)).
contacting websites.
adjuster 21b (what we used to call a 2pound hammer in my BT days).
slashing wrists!!!

HELP!!!!!!

Any assistance gratefully received; I know my way around a multimeter (and most white goods) as that is one of my ‘sidelines’ over here amongst the expats and some locals.

Many thanks,

Les Green
Alonissos,
Greece

Footnote – my last contact with Hotpoint, about 4years ago, they said that they were “unable to provide technical assistance or diagrams for their products due to Health and Safety legislation”. Being curious (and a stroppy bugger) I decided to pursue further and wrote to the HSE asking which particular section of H&S legislation precluded Hotpoint from giving this information to Customers. I received a wonderful reply about a week later, stating that the HSE were “unaware of any H&S legislation which would prohibit Hotpoint from giving out such information”, that it seemed that Hotpoint were “misquoting or were misinformed about H&S laws” and that (I LOVED this bit) “if Hotpoint cared to contact this guy (name & email address supplied) he would be more than willing to put them right”!
I emailed Hotpoiint with all this and (surprise, surprise) never received a reply.