Hi- I've had a new heating system installed (ASHP and some replacement radiators). Two of the radiators nearest the ASHP get hot. However the remaining radiators around the house only get hot at the bottom, say about a tenth of the height of the radiator, then cold above that. I've reduced the lock valves on the radiators nearest the ASHP, hasn't worked. I've tried bleeding the new radiators, and water comes out. Any ideas? (trying to preempt a wait of a few days before someone comes to check it again)