The landlord may enter a dwelling unit as follows:
(a) For the purpose of installing, repairing, or replacing a submeter, or for the purpose of investigating or rectifying a condition causing constant or abnormally high water usage, as required by subdivision (a) of Section 1954.210, if the requirements of Section 1954 are met.
(b) To read a submeter, if the requirements of this chapter and Section 1954 are met. Notwithstanding paragraph (3) of subdivision (d) of Section 1954, notice shall be given only in writing.