The Cowes Floating Bridge is expected to remain out of service until the end of this week.
A spokesperson for the Isle of Wight Council said:
“Having suspended the service over the weekend, our contractors have been onboard this morning and diagnosed the problem to be a defective heat exchanger.
“This is a bespoke part which can only be obtained via a supplier in Plymouth.
"This has been ordered, with delivery due in 24 to 48 hours. Once arrived, following fitting it is expected service to resume towards the end of the week.
“Whilst out of service, we will undertake routine maintenance which will reduce work needed in the future.
“The Isle of Wight Council apologises for any inconvenience. A replacement launch service will continue to operate for pedestrians and cyclists.”