If you’ve informed the tenant she needs to drain the pipe work when it gets cold enough, it’s her responsibility. If the landlord is paying, inform him of that necessity.
In regards to the shut off, if it’s too tight to fit in any gap to the side of machine (a real ball ache) she’ll just have to pull the machine out.
In regards to the shut off, if it’s too tight to fit in any gap to the side of machine (a real ball ache) she’ll just have to pull the machine out.