Mitsubishi wall unit srk50zg condenser src...

Mitsubishi wall unit srk50zg condenser src50zg air con, new installation. Indoor unit works in cool mode (not as cool as it should be). Indoor unit does not operate on heat mode but the outdoor condenser does. The indoor unit does try to blow, no error codes or flashing lights. Fins on indoor unit move on cool but not on heat. Would lack of 410A give me this fault? I have been told to check valves around condenser. At this stage i am considering buying a new condenser just to get the job finished.