Ka sport overheating issue

hi, i have a 2006 ka sport
after the car has been running for 5 minutes, the expansion bottle boils over yet the rad and lower hose are still cold
the heater only blows hot air even when its turned off
have replaced the thermostat, heater control valve and head gasket and now looking at the water pump

i have heard that there is a dodgy batch of heater control valves, is this the case? im not sure where to go from here as nothing is working at all

any help is appreciated
thank you