Kemerton XL

I agree with AutoSleepy_Don but just to clarify something, even when the Truma CP itself is OFF hot air is being blown from the Combi?  Or do you mean when the Truma CP is ON but the heating and hot water controls are off, the Combi blows hot air?  If the latter, what happens if you turn the Truma CP OFF (not APP) by holding down the button or won't it turn OFF? 

Assuming its an EC700, I wonder if it has got confused by not always turning the Truma CP to OFF before turning the EC700 power button off?

The next time it does it, it might be worth writing down the sequence of events and what you were doing with the controls at the time and what was being displayed on the CP.  Mine does funny things sometimes but generally it's OK.

tony.humphrey wrote:The Truma CP is on, heating and hot water controls are off.
Van now booked in to dealer as still under warranty - just. Wanted to ask if anyone had experienced the problem first as getting booked into a dealer these days seems to be a lengthy wait!
Will report outcome - if one found......

I will be interested to hear what the dealer or Truma say.  If it helps, I think we have experienced your problem but only infrequently.  It was associated with button pressing rather than coming out of the blue.  I can't be certain of the conditions that caused it and certainly couldn't replicate them.

I used to have Truma heating controls on the EC700 CP under setting as per page 15 of the Harmony manual but these were removed early on when I had a software upgrade to address another problem.  The Harmony manual recommends that the heating controls on the EC700 CP are not used.