if the heater coil isn't plugged why won't water circulate through it?
I have flushed my heater coil both ways and got clear water through it, installed a new
thermostat and still don't have flow. The top hose is hot bottom is cold going to the heater coil.
Did you get all air out of the cooling system after replacing the thermostat? If not it could be air locked.
Do you have a heater control valve? This device shuts off coolant flow through the heater core when you're using the air-conditioning. Kind of like shutting off a faucet. It may be stuck closed and preventing the coolant from flowing through the heater core. HTH. -Jim
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