From canada,heater blows warm heat in cold weather thermo replaced heater hoses are hot

One thing to remember about these particular engines is how to bleed them and that the casting when these are made leave behind some "mud" that can cause the same issue. start by flushing the system with a good chemical flush (follow the directions, about $10 U.S.) and when bleeding turn the heat on to high allow for engine to warm up with the resevoir cap off (please be careful).once the vehicles temp guage begins to rise, note the level in the resevoir and add if neccessary. replace the cap and hold to about 2000 rpms for a few minutes (not allowing the temp to get a little above half). note the temp coming out of the vents. there is a little bleed screw on the thermostat housing. it is brass so be careful not to damage this piece. when pouring in the coolant open this bleeder and allow for fluid to flow until no air bubbles are visible. then procede on. this should cure the issue as long as there are no other control issue faults (interior). cheers