Ok so I drained and flushed my whole central heating system. The system had 3 drain valves which I drained and also drained all the rads.
All went well but the last rad won't heat up. All rads are bled and the drain valve below the last rad runs hot water, so it's going through the rad with the drain valve open but won't continue round the circuit with it shut.
On this last rad the exciting pipe runs up a sharp 90 degree bend on its return up into a flat roof. Presumably it's air locked in the upwards straight?
What can I do to sort this?
I have no TRV's fitted on this system BTW.
All went well but the last rad won't heat up. All rads are bled and the drain valve below the last rad runs hot water, so it's going through the rad with the drain valve open but won't continue round the circuit with it shut.
On this last rad the exciting pipe runs up a sharp 90 degree bend on its return up into a flat roof. Presumably it's air locked in the upwards straight?
What can I do to sort this?
I have no TRV's fitted on this system BTW.