[axsaxoman]

to bleed system --get a 2litre coke bottle --cut bottom off--stuff the neck it into top of rad with a rag --then fill half way up - open bleed points till you see water--then run car with bottle still in till its water starts getting some temp in it --stop car -open bleed valves again --do not bleed with engine running--- run for a little longer --then remove bottle and fit cap --should be no air in engine now -- you cannot run it till full hot as it will just boil in head and blow water back up into bottle if no rad cap on

then run till fan comes on -if thermostat+ fan is working that should be about 10mins and fan should go on +off
If it is a h/gasket problem one of 2 things will happen --pressure will keep building up and temp will be getting hotter + fan on all the time + cap will blow off
OR water will leak into engine and little or no pressure will build up in system --squeeze hoses to feel if it is building up pressure as it warms up --eventually water may boil in head and water level will be low
check it WHEN it has cooled down --DO NOT open cap when its hot cos it will instantly boil and throw all the water out .
If your heater is blowing cold its full of air or its blocked with crap --