[R5T]

To clarify any un-certainty,

I was trying to flush the system due to the cruddy water in the expansion tank. Obviously there is going to be cruddy water in the block and head as well ... I dropped all the water from the radiator and expansion tank, put all hoses back on and filled the tank up again.

I started the car and once the engine had reached temperature I was expecting the "thermostat" to open and let the water from the tank/radiator flow through the whole system ... It didn't.

This is why I asked in my first post "Is there any other way of telling whether the thermostat is working correctly ?" ... i know how to bled the system with the heater matrix pipes etc. My queery was only with the thermostat.

Thanks to all that made an input, the thermostat is now out of the engine and I have succesfully flushed the whole sytem of the cruddy water.

Thanks again

Sam