Halstead Ace HE24 Fault code ?

My Mum's Halstead boiler is showing fault code C, hot water fine but no CH any suggestions ?
Kevan, October 2013


done
Thank you for the reply but the C is not flashing it is constant ! any idea how I get it out of service mode ?

Kevan, October 2013
A flashing 'C' indicates that the boiler is in Service Mode and that the boiler will fire continuously at minimum input.
This setting is for the convenience of the Service engineer ONLY.

A1, October 2013
link Click here to see other fixes for Halstead Ace.