How do you affect the supply of water to the radiators?
Solid fuel, water in tank hot but radiators not heating up any more than warm. Pump works ok, radiators have been bled - no air escaping - and no thermostat (all or nothing I'm afraid)!
Once the water in the tank reaches temperature
Thee problem could be that you have an airlock in the pipework to the rads and not the rads themselves. If you can, turn off the valves on the furthest rad from the boiler, and drain the rad by undoing one of the valve joints and let the water run into
