CalMac hopes to have Hebrides back in service on Sunday following work to its firefighting system.
The ferry was hit with a similar problem last week.
CalMac, which posts service updates on its website, external and its social media, has issued an apology to its customers, and appealed for patience with its workers while they try to meet demand.
Managing director Robbie Drummond said: “Moving vessels around is not ideal but without any spare tonnage to use during disruption, it is often the only available option we have to continue to operate lifeline services.
“I can assure customers that we have looked at all possible alternative options before coming to this decision.
“I am deeply sorry about the effect that the loss of MV Hebrides has had on our passengers and communities.”
Earlier this week, Transport Scotland said the Scottish government was investing in CalMac.
A spokesman said: “Ministers recognise that having confidence in ferry services can impact upon people’s decision on whether to live and work on the islands, and impacts upon the sustainability of the island communities themselves.
“These human impacts are at the heart of Scottish ministers’ commitment to continued investment in ferry services across Scotland.”
He said with government support CalMac, and its parent company CMAL, had sought to ease pressure with previous charters of a freight ferry and the purchase of the MV Loch Frisa, a former Norwegian passenger ferry.
On Friday, the Scottish Liberal Democrats called for the Scottish Parliament to be recalled for an emergency statement.
The Scottish government has been approached for comment.
