Sailings of the high-powered trimaran Liberation have been cancelled since Friday because of steering problems.
Passengers had been due to be transferred to the Clipper ferry, but that broke down on Saturday morning.
Condor said the Liberation would be back in service on Tuesday on the route between the Channel Islands and Poole.
The firm has apologised to customers and offered refunds.
It said Monday's Liberation passengers would be transferred to the Tuesday services and its booking staff would work until late on Sunday.
Passengers were delayed embarking at Portsmouth on the Clipper for 12 hours on Friday after a ramp failed.
The ramp was being fixed on Sunday and the Clipper is expected to sail again on Monday.
The firm said fixing the ramp on the Clipper required a specialist crane, which delayed the work.
"We could have lowered the ramp more quickly, but that could have caused permanent damage, so we took the prudent approach of sourcing a specialist crane to lower it, that's why it took longer," said a spokeswoman.
Condor's executive chairman, Russell Kew, said: "I'd like to apologise to all those customers who have been inconvenienced over the last 24 hours, and to thank them for their understanding and patience."
Ferry passengers between the Channel Islands and the UK face major disruption on Monday with Condor's fast service out of action for a third day.