Hi, I have a 2009 York Chiller on a client site, model no. YLAA455HE on R410A. It went out on a low pressure fault recently, dug deeper and found the controller had reverted back to R22 refrigerant. Checked program settings and was unable to change it back to R410A. Anyone got any ideas how to change refrigerant type on this model or do I need to reload the programme?