CA 21 January 1991. The plaintiffs P instructed a firm of surveyors M to carry out a structural survey of a house before purchase. M indicated that they were not competent to give any opinion about the heating system . P gave them permission to instruct a specialist firm of heating engineers , E. The survey claimed the system was working satisfactorily. P therefore bought the house and moved in in December 1987 and began to use the heating. It did not function correctly and the gas board and a firm of specialist engineers were called in. A crack was found in the heat exchanger although a representative of E claimed it was rust. On further inspection a more serious crack was found on the other side of the system and it was condemned. A new heating system had to be installed. P commenced proceedings claiming that E should have discovered and reported the crack at survey stage. The original hearing held in favour of E on the basis that it was not usual in such a survey to inspect the heating system.