So you are saying you went for months without using hot water? no one in your household ever had a bath during that period? Because I can understand the heating not being used in the summer but hot water is a different story....
I recently bough a house only to find on the day of completion that the boiler was not working. To me that is unacceptable and I don't believe for a minute that the sellers were unaware of it...
They had declared on the conveyancing forms that the system was working and provided a copy of the most recent boiler annual check as evidence. The boiler worked when the home survey was done. I would absolutely expect the sellers to have the decency to declare that the boiler had subsequently broken down before completion and either offer to try to fix it or to take some money off the selling price.
They also left in the house a bunch of furniture, old curtains everywhere and more stuff in the shed and garden.
I asked my solicitor to write to them telling them that I expected them to reimburse me for having to dispose of the crap they had left and to pay half the cost relating to the boiler.
This is a small town and all the neighbours soon became aware that they had left me with a lot of stuff to clear out, a broken boiler as well as a leaking toilet which damaged the ceiling below. In the end that's what pushed the sellers to respond positively to the solicitor letter as they realised their reputation has taken a serious hit and people were talking....
Frankly the home buying system in England is a joke and it allows too many greedy and dishonest sellers to hide issues and get away with it...It needs some serious reform.