TRVs recognising when a call for heat has failed

SamN

I got up to a cold house this morning. I looked in the app and all TRVs were “heating to 20°” however, despite it being 8.15am and my schedule being set to start heating at 6.45/7am all rooms were still only 16° or thereabouts. It turns out my combi boiler had dropped pressure resulting in the boiler being unable to fire and I don’t understand why the fact heat was called for but didn’t happen did not create an alert when I know of other members whose boilers have failed to fire up due to an issue like a frozen condensate pipe and the app has informed them it’s detected an issue with rooms not heating as they should. This needs improvement as I feel the very fact bo change in temperature was happening after 90 mins of calling for heat the “smart” TRVs should have detected a heating failure.