It is in your LL’s interest to look after the fabric of the building but you have responsibilities too.
Condensation is a big issue throughout the UK but there are sites on the internet to help you deal with it. For example, do not dry your washing on radiators, cover pans when boiling food, shut bathroom door when showering & afterwards, always use trickle vents if fitted, in window frames.
Out tenant (we’ve sold the flat now) had ringing wet walls & condensation on all windows. This was because she was not trying to minimise the issue by using the extractor fan in bathroom and carried on drying washing on radiators etc as above.
We felt it was our responsibility to provide a dehumidifier which helped enormously. We were prepared to do anything to preserve the internal walls etc. from mould and help her to help herself. We engaged a consultant to review matters and it was he who gave her lots of tips to avoid issues but the condensation was down to “life style” which is very common.
As it was she had too much furniture & “stuff” piled up against the walls so air didn’t circulate and caused black mould. Keep furnishings at least 2 inches off your walls especially wardrobes, dressers and sofas.
In the end our tenant moved in with her new boyfriend and we were able to sell up.
Before she moved in the flat was bone dry. We remain in touch to this day,
Try getting in touch with Shelter for advice about the legal ramifications of your LL bring unhelpful.