Whale Watermaster ICU

Connected up aquaroll full of cleaning chemical to flush through van pipes the other day and found water system not working.

Spoke to storage site manager who found first a blown fuse on the pump circuit which was replaced and then the yellow Whale ICU needed recalibrating which he proceeded to do. Couldn't get it working despite following all instructions from Whale website. Rang Whale and they talked him through various tests resulting in Whale engineer deciding the ICU was bust (two years old and working 10 days ago at the service) so I went off to a local caravan shop and purchased another ICU for £49.95.

Manager refitted it and initially it worked, then we tried again and it didn't. Went though various tests and again spoke with Whale who again decided the ICU was faulty. Took it back to the shop who swapped it for the last one on their shelf.

This was refitted and the same thing happened, it initially worked then failed.

One of the tests was to remove the ICU and wire up directly to the terminals of the inlet socket and we could get the water running by turning the pump on and off via the whale intelligent control panel, so all other items in the water system are working.

Again the Whale engineers suggested getting another ICU but the manager pointed out this was the third failure and buying another one with no guarantee it would work was unreasonable.

Whale agreed to send out another inlet socket which will arrive shortly and be fitted. I believe the one they are sending out is the previous generation inlet socket without the ICU and has a manual adjustment for the voltage levels.

My question is has anyone else come across repeated failures of this Whale ICU and what was the problem and solution?