It doesn't matter which end the TV is on provided it is bi-direction, and flow will always get hot first, unless the system is connected wrong, eg an extra radiator has been added, in which case you could get reverse circulation.
Under normal operating conditions it seems that nothing gets hot, which indicates an air lock.
We are assuming the divertor valve is switching over to heating, and there isn't any taps dripping etc.
Under normal operating conditions it seems that nothing gets hot, which indicates an air lock.
We are assuming the divertor valve is switching over to heating, and there isn't any taps dripping etc.