The eight-seater vessel is operated by Salty Blonde and has faced a challenging 2022 before the latest round of issues.
The company said it was sad and disappointed to confirm the vessel was facing further mechanical issues.
‘We do not yet have a diagnosis of what has caused the failure, nor a prognosis of how long repairs will take,’ it said in a statement.
‘We think it is only right not to resume services until we have a boat that we are confident will operate reliably as an inter-island ferry.
‘We most certainly never anticipated this catalogue of issues with Ashlin and can only apologise again for the inconvenience caused to our customers.’
The company is contacting customers and supplying full refunds.
‘Thankfully, we made the correct choice to invest in the Causeway Explorer and Alderney Ferry Services earlier this year,’ Salty Blonde wrote.
‘We have been in discussions with them about our customers and they will be putting on extra rotations where possible to accommodate our passengers.’
Alderney Ferry Services has asked people to be patient because they have to deal with a high volume of calls and emails.
The Ashlin started operating in April but had to stop in early May due to a technical problem, with parts needing to be sourced overseas. It went back into action in mid-June.
Salty Blonde wrote that it was sad to have further problems.
‘After our commitment to not let anyone down during the highly successful Alderney Week – working with many charter boats which pulled out all of the stops to assist us – and our determination to continue until the end of the season, this comes as a considerable blow to us and our valued passengers.’
Alderney Ferry Services also faced a challenging start to this year when its first vessel was found to have serious underlying engine problems.
But by early July both companies’ vessels were operating smoothly and Salty Blonde, which is subsidised by the States of Alderney, helped finance the 12-seater Causeway Explorer for Alderney Ferry Services.