The results of five thermal response tests (TRTs) are presented. Three of the tests were carried out consecutively on the same borehole to illustrate the importance of allowing artificially imposed thermal gradients to dissipate prior to commencement or re-commencement of a test following testing issues. The two remaining tests carried out on separate boreholes confirm the results obtained by the first (uncompromised) of the initial three tests. The testing regime demonstrates the necessity of careful performance of TRT's and shows the variation in costs/required borehole length which may occur if testing problems occur on site. Copyright , Oxford University Press.