Upon his/her own initiative, or upon application of any party in interest (including an employer or carrier which has been granted relief under section 8(f) of the Act,
33 U.S.C. 908(f)), the district director may review any compensation case (including a case under which payments are made pursuant to section 44(i) of the Act,
33 U.S.C. 944(i)) in accordance with the procedure in
subpart C of this part, and after such review of the case under
§ 702.315, or review at formal hearings under the regulations governing formal hearings in
subpart C of this part, file a new compensation order terminating, continuing, reinstating, increasing or decreasing such compensation, or awarding compensation. Such new order shall not affect any compensation previously paid, except that an award increasing the compensation rate may be made retroactive from the date of injury, and if any part of the compensation due or to become due is unpaid, an award decreasing the compensation rate may be made effective from the date of the injury, and any payment made prior thereto in excess of such decreased rate shall be deducted from any unpaid compensation, in such manner and by such method as may be determined by the district director or the administrative law judge. Settlements cannot be modified.