Thank you for your reply. Yes the pump is on maximum (3) and the plumber has come back and fiddled with a valve and all radiators are now nice and hot.
Emsi.
My boiler (Ideal mexico) started making an awful noise (crackling) a few days ago and eventually yesterday morning all radiators on ground floor were cold, top floor ones lukewarm and we had little hot water (timer on for both and wireless thermostat set to 22C). Plumber diagnosed a faulty pump and ...