Why does the radiator in your lounge not warm up even though you have bled the radiator?
I'm supposing all other rads on the system are hot? If so, it sounds like you either have a flow problem, check wheel-head and locksheild valves are open. If they are you'll need to determine if water is actually passing the valve when open by un-doing the joint. I assume when you bled the valve air followed by water under pressure followed? If this occurred it's likely there is suitable flow and that the radiator itself is blocked with sediment.
The most cost effective measure is to remove rad and flush out individually with hose pipe, remembering to lock of valves before hand.
Observe how much silt/rust deposits comes out. Flush till clean and refit, open valves and re-bleed, see how you go. Are you using inhibitor in the system do you have an engineer service it every 12 months.
Why would the internal heating of a 2001 deawoo leganza not be working even thought the engine thermostat has been replaced and the systme has been bled?
Make Sure That Your Fan Is Running For Cooling The Radiator. Put A New Thermostat Back In. It Will Run Hot Without One. The Water Will Not Stay In The Radiator Long Enough To Cool. If This Doesn`t Help, Have a Good Radiator Shop Look At It For You. Also You May Want To Resumit A Question as To What Happened If This Did Not Cure The Problem. Thank You