Completely new to this forum and only had Daikin Altherma HT installed in less than a week ago by my installers.

Tonight around midnight the temperature symbol / icon which I am sure is always on has started continuously flashing and I have noticed no heat is being produced through the flow pipes and upstairs on radiators has started to cool down.

Will have to call installer in morning but just wondered if anyone knew what it could be incase it something very obvious for a beginner like me!

Thank you!