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No just the thermoDid you open the bleeds on either side of the block after draining the system or just the one on top of the thermostat?
Yes both replacedTry tightening all hoses, then get the engine up to temp, then re-bleed it. Do this (bleed) with the heater on high.
Also after going for a drive (going to shop, whatever) bleed it again.
Do this 2 or 3 times, or maybe more. No air may not come out of it, when bleeding, but by doing this a few times, you will eventually get all the trapped air out.
You've replaced the water pump & heater tap haven't you?