The original point was about the original design and build quality, not maintenance. Angel, as the owners, are the ones that would need to talk to Althom.But HT are responsible for maintenance, not Angel...
Sale of Goods act 1979
14 Implied terms about quality or fitness.
(1)Except as provided by this section and section 15 below and subject to any other enactment, there is no implied [F15term] about the quality or fitness for any particular purpose of goods supplied under a contract of sale.
[F16(2)Where the seller sells goods in the course of a business, there is an implied term that the goods supplied under the contract are of satisfactory quality.
(2A)For the purposes of this Act, goods are of satisfactory quality if they meet the standard that a reasonable person would regard as satisfactory, taking account of any description of the goods, the price (if relevant) and all the other relevant circumstances.
(2B)For the purposes of this Act, the quality of goods includes their state and condition and the following (among others) are in appropriate cases aspects of the quality of goods—
(a)fitness for all the purposes for which goods of the kind in question are commonly supplied,
(b)appearance and finish,
(c)freedom from minor defects,
(d)safety, and
(e)durability.