Brilliant - many many many thanks - I turned the valves on for a few seconds and hey presto I now have heating again!
Only one problem - being under the boiler I also noticed a slight leek coming from the bottom of my boiler - it's not drastic but it's definetly leaking water from somewhere...
Hello - today I bled some radioators - one of them I let some water flow out (about half a cups worth) about 30 mins later my girlfriend went to have a shower and reported no mhot water - I touched the radiator and noted they were now cold.
The boiler is showing an illuminated safety lockout...