The Engineers will arrive on site, begin to diagnose the issue and once diagnosed, discuss the necessary parts required with you before changing the parts over. Once these parts have been changed, they will stay with the Hot Tub for a while to be sure that it is functioning correctly. The Engineer Call Out fee will be charged prior to the Engineer's attendance, and if any parts need changing, they will be charged on the day. The Engineers carry the majority of possible spare parts; however, in the unlikely event of a second visit being needed, this would require a further Engineer call-out fee. (Please note, Hot Tubs that are out of warranty will incur extra charges for any parts used)