I have a b20z in my 2000 civic and the motor had allmost over heated so i changed the thermostat and in the process i relized there wasnt hardly any water in the radiator lol after i had gotten it all back together the temp guage was normal but the bottom radiator hose was still cold and i had hot heat. I didnt put any anti freeze in it so i could make sure it was working correctly. Ive cheaked my oil and theres not any water in it or at least it isnt milky so do you guys have any advice thanks alot. brandon

Did you run the motor with the radiator cap off for a good while with the heater on high??? You need to do this, it bleeds all the air out of the coolant system. Fill up radiator with coolant, leave cap off, start car and leave in park, turn heater to high and let everything run until the radiator fan comes on and the T-stat opens. Both upper and lower hoses should be quiet hot to the touch.

okay thanks is there any thing else it could be

Could be a plugged radiator. Look into the radiator and see if there is any rust build up on the cooling fins inside. If the coolant was clean not red and rusty you should be fine. The lower hose will stay cool until the T-stat opens up and coolant starts flowing. Keep in mind that Hondas take a while for the T-stat to open. The head and upper hose will be hot.

Are you using oem or aftermarket one like autozone? I always run into problem with the cheap autozone one, so I recommend getting oem one.