had the same problem last night - defrosted - disconnected & emptied and still no joy- I then soaked up all of the moisture from around the condenser drain connections at the top and gave it some hairdryer. after on/offing & resetting a few times it started back up for the hot water first then the heating was fine - I guess that all the moisture has to be gone perhaps a short or something.
shipwreckmark
December 2010