Four in 10 Brits have used their annual leave to stay at home waiting for someone to fix their broadband, according to a study.
Some remain without Internet access for months at a time, found thinkbroadband.com, which conducted a survey of households.
And a total 19% of respondents had to rebook the visit of an engineer at least once, added website editor Andrew Ferguson.
He said: "The amount of time wasted on engineer call-outs and re-bookings is a major inconvenience for thousands, but it is the prolonged disruption to internet access that has the real impact on people's everyday lives, and especially for businesses."
Openreach provides two million premises with high-speed fibre network access to ISPs including Sky and TalkTalk, as well as BT's own retail broadband service.
The company has faced long-standing criticism over the reliability of its engineers and contractors, with BBC Watchdog registering hundreds of complaints from those left without telephone or internet access for weeks or even months.
However, Openreach claimed it carries out 60,000 jobs every week and that the majority are completed without issue.
Ferguson added: "Reliable broadband has become incredibly important, to the extent that it is considered a basic amenity by many, and network providers should treat faults and installations with the same level of urgency expected for power, water and gas call-outs. It is essential not only that attendance levels improve, but that customers are kept much better informed of progress and delays."