United spokeswoman Mary Clark says Flight 125 on Tuesday from Heathrow Airport to George Bush Intercontinental Airport was canceled due to problems with a message indicator. Further details weren't immediately released.
United officials say the 211 passengers on the jet, which Boeing calls the Dreamliner, would being scheduled out on other flights Wednesday.
A United Boeing 787 bound from London to Houston on June 20 - also listed as Flight 125 - diverted to Newark, N.J., because of a low engine oil indicator.
The Dreamliner faces more scrutiny than normal because it was grounded for three months earlier this year amid concerns about overheating lithium-ion batteries.