My heater will only blow out cold air, I stripped it down and found that there`s no hot water flowing to the heater matrix. Before wasting money, i just wanted to know if someone can answer my question.

Is the reason why my heater is not getting hot, because the heater matrix is broken and will not let the hot water flow through it, or could it just be an air lock in the system

mark, October 2009

if the heater doesnt get hot try and put the jet wash blowing down one of the pipes and it may free it up, i have done this on one of my own and t got a lot better

zak powell, January 2010

couple of things you could check, all the models in the discovery group suffer from an outside temp sensor issue the only fixis to replace the sensor,it is found on the middle of the radiator,
obvious things to check are the thermostat,and also the heater matrix thermostat.hopefully you will just need to bleed the water system again. worst case senareo is head gasket, the expantion water bottle would get pressureized very quickly if this was the case.there is a self diagnostic test for the aircon which will give an error code for the outside temp sensor failour (code 12) and heater matrix temp sensor fail (code 14) to access code do the following:-
ignition OFF
hold down auto & AC/heater direction switches.
turn ON ignition
listen for audible warning.
AC is now in diagnostic mode
If any error's are found the letters FC will be seen next to each error code.
turn OFF ignition...

ian, October 2009