KCom, previously known as Kingston Communications, lost all internet access on Saturday afternoon at 3pm and was not able to restore it until 10pm that evening.
KCom, which has an effective monopoly in Hull, said it had engineers working on the problem and to ensure it does not happen again. The last time this happened the city was plagued with intermittent faults for much of the following week.
Business and residential customers were affected, as were communications between hospitals.
The last failure was blamed on a network upgrade, but a Reg reader and Hull resident said: "It's just not good enough not to have a back up or regression plan and we've had no explanation either."
KCom sent us this statement:
"We had a significant network failure on Saturday 9 August starting at around 3pm with service being restored at about 11pm.
This affected our Karoo and Kingston Communications customers, who were unable to connect to the Internet. Working with our suppliers, Nortel and Cisco we isolated the issue to restore service.
Engineers worked throughout Saturday night and Sunday 10 August to ensure service was stable.
We sincerely apologise for any inconvenience this caused our customers who were trying to access the Internet during this period.
We are working to understand the exact root cause of the issue and ensure that appropriate actions are taken to mitigate the risk of it happening again."