Hi fridge_bloke

your last post has me wondering now too

Does this controller have the ability to monitor a logarothm based upon water temp and suction pressure - anyone ???

Say with R407c it will alarm at 3.6bar.g 0*c

But does it have the ability to look at say 15*c water outlet temp with a 4.0bar.g suction pressure and alarm on diff pressure to high and say 15*c water outlet temp and 6.0bar.g suction pressure being to low - anyone ???

To illiminate mate, if no-one does give a definitive answer prior to your return, I would check suction pressure and superheat on both circuits - against the same water leaving temp and look for a rather large difference

If not I would still be inclined like yourself to suspect the controller

R's chillerman