Sharing what I discovered from recent ‘no heat on 2005 Prius. Suddenly this winter had zero cabin heat. Heater hose from 3 way valve not hot. After some investigation, no blockage thru heater core.. so had to be 3-way valve… which I already replaced last year for occasional code issue. This time I got a OEM Toyota valve and drained all the coolant. I was able to replace 8 quarts by opening the drains and blowing air thru heater core hose. I followed all the tricks on this site for bleeding. DEFINITELY USE A TALL FUNNEL AND MASSAGE THE RADIATOR HOSES!! If u do that, it’s easy to get air out… thanks everyone for great advice
